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^
F. B0RGESEN
THE MARINE ALG^E
OF THE DANISH WEST INDIES
VOL.11. RHODOPHYCE.E
ter
WITH ADDENDA
TO THE CHLOROPHYCE.E, PH^EOPHY
AND RHODOPHYCE^:
COPENHAGEN
PRINTED BY BIANCO LUNO
19151920
Part
1
(pp.
1
80) appeared
12
/ u 1915
2
(pp.
81144)
CONTENTS
Introduction
Pag.
1
Rhodophijcese
3
List
of
the
Chlorophyceae,
Phseophyceae
and
Rhodophycese
found
at the
islands together with addenda and corrections:
Chlorophycese
413
Phseophyceae
.
431
Rhodophycese
445
General remarks:
Definition
of species
485
Some remarks concerning the
algal vegetation
at the islands
486
Some remarks
on
the
geographical
positions
of
the West
Indian
algal
flora
491
Concluding remarks
,
496
Index specierum
499
INTRODUCTION
J\s was the case with the parts
of "The marine Algae of the
Danish West Indies" published
earlier,
this third
part, containing
the Rhodophyceee, is based especially upon materials collected during
my three stays
at the
islands.
With regard to West Indian Red Alga?
I have already published
some papers on the
subject, namely:
Some new
or
little known West Indian
Florideae,
I.
(Botanisk Tids-
skrift,
30. Bind, Kebenhavn
1909).
Some new or
little known West Indian
Florideee,
II.
(Botanisk Tids-
skrift,
30. Bind, Kobenhavn
1910).
For the sake of completeness
I have included here the principal
contents
of these papers.
The Red Algse
are common in the
literal region and
also
in
the
upper
sublitoral,
but
they
occur
especially
in
deep
water,
and
where
I succeeded
in dredging in such places
I always had
good
results.
Thus
they
occurred
abundantly
in
the
Sound
between
St. Thomas
and
St.
Jan.
Strong
currents
run
here
in
the
narrow channel and steadily renew the water.
The depth
varies
from 10 to about 20 fathoms, seldom more. The bottom is suitable
for dredging
;
it
consists
of
smaller and
larger stones,
pieces
of
corals
etc. Upon these a very rich vegetation
of
algae
is present,
mostly
consisting
of Red
Algae.
Also
north
of
St.
Jan,
in the
narrow sound between
this Island and Tortola, a flourishing algal
vegetation
is found, including especially many Red
Algae.
1
At St. Thomas
I have dredged in the sea around Water Island.
At a depth
of about
10 fathoms and upon sandy,
loose bottom
a vegetation
of
Udotea and Halimeda was found, together with
several
Florideae.
At
St.
Croix
the
dredgings were mostly
not
successful
on
account
of
the
coral
reefs which
almost
entirely
surround
the
island.
Only in the sea near Buck
Island have more
successful
dredgings been undertaken.
I much regret that
I have not succeeded in dredging in deeper
water than about
20
25 fathoms
;
as pointed out
in the
intro-
duction
to
the
Chlorophycese
section, my attempts
at
this were
negative, the dredge being immediately lost in the rocky bottom.
But
it
is not only
in deep water that the Red Algae occur;
also in shallow water near the shore they are often found
in great
numbers.
In
connection with
this may
also
be
borne
in mind
the
rich
algal
vegetation
upon
the roots
of the mangroves and
among which the red
alga? are very
prominent.
1
)
With regard to the physiographical details,
coral reefs, depths
etc. and also
to
localities visited,
reference should be made to the
introduction
to
the
section
on
the
Chlorophycese
;
in
this
part
moreover a chart
is published showing the coral reefs, depths etc.
in the
sea surrounding the
islands.
Compare my treatise
: "The algal vegetation of the lagoons in the Danish
West
Indies"
in
"Biologiske
Arbejder
tilegnede
Eug. Warming
den
3. November 1911",
p.
41.
RHODOPHYCE^:
A.
Protoflorideae.
I.
Bangiales.
Fam.
1. Bangiacece.
Subfam.
1.
Goniotrichieae.
Asterocytis
Gobi.
1.
Asterocytis ramosa (Thwaites) Gobi.
GOBI,
C.,
in Arbeiten
St.
Petersb.
Naturf.
Ges.,
Bd. X,
1877,
p.
85.
SCHMITZ, FR.,
in Nuova Notarisia,
1894,
p.
717;
id.
in ENGLER u. PRANTL,
Nat. Pflanzenfam.,
I. Part,
2. Abt., p. 314.
WILLE, N., Algolog. Notiz.,
I
IV
(Nyt Magazin
f. Naturv.,
Bd.
38,
1900,
p.
7,
tab.
1,
figs. 814).
ROSEN-
VINGE,
L. KOLDERUP, The marine Alga? of Denmark,
1909,
p.
77.
Hormospora ramosa Thwaites in HARVEY, Phycologia
Brit.,
pi. 213.
Goniotrichum ramosum Hauck, Meeresalg.,
p. 517.
BATTERS, Mar. Alg.
Berwick,
p.
13; LAKOWITZ, Algenfl. Danziger Bucht,
1907,
p.
79.
Growing upon specimens
of Liagora elongata
I
have
several
times found a small
alga which undoubtedly belongs to this genus
and
as these specimens seem
to
differ in no
essential way from
A. ramosa
I have referred them to
it.
The specimens found were often rather large and repeatedly
branched
(Fig. la);
in some specimens the vegetative
cells were
nearly globular or subquadrate, about
as long as broad,
in others
the
cells were oblong or
ellipsoidal
(Fig.
1 b).
This plant
has
been
recently examined
in
detail by WILLE
(1900,
1. c.) and by ROSENVINGE (1909,
1. c.).
WILLE describes the
setting
free
of the spores which
is
as pointed out by ROSENVINGE
in
accordance
with
the
earlier
description
of
SCHMITZ.
WILLE
describes
furthermore
some
few
cells with membranes which he
supposes to
be
akinetes.
ROSENVINGE has now stated that the
supposed
akinetes
of WILLE
are
really
such.
He was
fortunate
enough to
find filaments
in which nearly
all the
cells were trans-
formed to
akinetes.
l*
4
In my material also
I have found
several times filaments in
which
the most
part
of
the
cells were
transformed
to
akinetes
(Fig. 1 d).
These cells had each a very thick wall (about 2^ thick)
of
a
firm
consistency,
while
on
the
other
hand
the common
membrane
in
the whole
filament
is thin agreeing with the
des-
cription
of ROSENVINGE.
The akinetes escape through a hole
in the membrane
of the
filament (comp.
fig.
1 d).
They have very dense granular contents
and
are often oblong, sometimes
also globular
or
ellipsoidal; their diameter reaches a length
of about
14//.
The filaments reach a thickness
of about
16
21^, 'while the vegetative
cells are about
6
1 /u.
In one case a specimen was found in
which the main filament was about 25^ and
the diameter of the
cells about
10 p while the
branches only reached the thickness mentioned
above.
ROSENVINGE
also
mentions
that
he
has
found
a
single
specimen
of
a
similar
thickness. The chromatophore is, as well known,
starlike
(Fig. 1 c).
Having only examined specimens preserved
in
spirit
I
cannot
say
anything
as
to
the
colour of the
plant.
As several authors have
stated that they have found Asterocytis ramosa
in
brackish
water
(comp.
ROSENVINGE,
1.
c.
p. 78)
I may add that the plant
in the West
Indies was found
in quite
salt water.
Found
upon
Liagora
elongata
at Long
Point,
St. Croix.
Geogr.
Distrib.
Atlantic
coast
of
Europe,
Mediterranean Sea, North America.
Fig.
1.
Asterocytis
ramosa
(Twaites)
Gobi,
a, part
of a
plant,
b, summit of
a filament with lon-
ger
cells.
c,
cells
with
chromatopho-
re.
d, part of a
fila-
ment with akinetes.
(aandfc,aboutl25:l,
candd, about 200:1).
Goniotrichum Kdtz.
1.
Groniotrichum
elegans (Chauv.) Le
Jolis.
LE
JOLIS,
Alg. mar.
Cherb.,
p. 103.
BERTHOLD,
Bangiacea?,
p.
26.
HAUCK, Meeresalgen,
p.
518.
RO-
SENVINGE, Marine Alg.
of Denmark, part
I,
p.
75.
Bangia
elegans
Ghauvin,
Alg.
Norm.
no.
159
;
Mem.
Soc. Linn. Norm.,
t.
6, 1838 (not
seen),
id., Recherches
.
.
d'Algues,
Caen.
1842,
p. 33.
HARVEY, Phyc.
Brit.,
pi.
246.
Bangia Alsidii Zanard.,
Bibl.
Ital.,
t.
96, 1889 (not seen);
id., Synop-
sis Alg. mar. Adriat. (Memorie
d.
r. Accademia
d. Scienze
di Torino, Serie
II, Tomo IV,
1842,
p.
217,
tab. VI,
fig.
7).
Goniotrichum Alsidii (Zanard.) Howe, The
marine Algae
of Peru (Me-
moirs
of the Torrey Botanical Club,
vol. XV,
1914,
p.
75
1
).
The specimens found reached a
length
of
about
1 mm.
;
at
their base they were
about
25
35^
thick,
at the summit only
about
15//.
They are fixed to the substratum by means
of
a small
disc
formed by the basal
cell
(Fig. 2 c).
Fig.
2.
Goniotrichum elegans (Chauv.) Le
Jolis.
a and
b,
parts
of
the
thallus
showing
ramification,
c,
base
of
a
plant.
d, summit
of plant with longitudinally divided
cells.
(About 150:1).
The filaments
(Fig. 2 a and
b)
consist
for
the most
part
of
a
single row
of
cells
and
in some
specimens these
were
almost
the only ones which occurred, but several specimens had filaments
which more
or
less consisted
of 2
3 or even 4 cells
in transverse
section.
The
cells
in
these
filaments
are
irregularly
arranged,
J
) The reason
I do not follow Dr. HOWE
in using ZANARDINI'S name for
this species
is because
it seems
impossible judging from ZANARDINI'S
description and figure to say quite certainly which species
of Goniotri-
chum we have
to do with.
occurring
in
irregular rows.
These specimens certainly approach
the
form
described by BERTHOLD
in
his "Bangiacese"
p.
26
as
Goniotrichum dichotomum and
found
in
the Gulf
of Naples,
but
he found up to
eight cells
in a cross
section of the
thallus while,
as mentioned above,
I found 2
4 only.
HAUCK
refers BERTHOLD 's
plant
to
Goniotrichum
Cornu
Cervi
(Reinsch)
Hauck l
)
but
in
this
species there
are many more
cells together in the filaments
at
the same
level.
My plant evidently comes very near
to the
form
from
the
coast
of Peru mentioned by HOWE
1.
c.
In the specimens from the Danish waters which are
figured
and
described by ROSENVINGE we
find now and then more than
a
single
cell
at
the
same
level.
According
to
ROSENVINGE'S
statement
this was
caused
in
the
specimens
examined by him
not by
longitudinal walls
but
by displacement
of the
cells.
In
addition
to
this way
of
obtaining
several
cells
in the filaments
the multiplication
of the
cells
in my plants
is certainly
also due
to longitudinal
division
of the
cells (comp.
fig. 2 d).
The
cells
contain
a
starlike
chromatophore
with
a
central
pyrenoid.
In
the
filaments
consisting
of
a
single row
of
cells
these
are mostly short, often only a fourth part of their diameter;
the most common is that about half their length, more rarely they
are about as long as broad.
The diameter of the cells
is about 12^.
In
the
filaments
on
the
other hand
consisting
of
several
cells these are most often about as long as broad and by mutual
pressure
of irregular polygonal shape.
The
ramification
is
described
in
detail by ROSENVINGE;
it
reminds one
as
is well-known
of the so-named
false branching of
the Scytonematacese.
Concerning the reproduction ROSENVINGE has not made any
observation and
I have not succeeded in finding anything in my
material.
The
plant
is
found
partly
upon
other
alga?
partly
upon
different substrata
e.
g.
old
pieces
of
tree
etc.
It seems
to be
a common plant
at the
islands.
St. Thomas: French Wharf.
St. Jan: Near America Hill.
St.Croix:
Ghristianssted, Lt. Princess, Frederikssted and other places.
Geogr. Distrib.
Europe, Mediterranean Sea, Maroc, Peru.
HAUCK,
F.,
Meeresalgen,
p.
17.
This
species was
first described by
REINSCH
in "Contributiones",
vol.
I,
1875,
p.
40,
pi. XV and here
called Stylonema Cornu
Cervi.
Subfam.
2.
Erythrotrichieae.
Erythrotrichia Areschoug.
1.
Erythrotrichia carnea
(Dillw.)
J. Ag.
J. AGARDH,
Till Algernes Systematik, VI, Ulvaceae (Lunds Univ. Ars-
skrift,
t. XIX,
1883,
p.
15.
ROSENVINGE,
Mar. Algae
of Denmark, part
I,
1909,
p.
67.
Conferva carnea Dillwyn,
British Conferv.,
1809,
pi. 84.
Conferva ceramicola Lyngb., Hydrophytol.
1819,
p.
144,
pi.
48 D.
Bangia ceramicola Chauvin, Recherches sur 1'org.
.
.
.
d'Algues, Caen
1842,
pag. 2930; HARVEY, Phycol.
Brit.,
pi.
317.
Erythrotrichia ceramicola
Aresch.,
Phyc. Scandinav.
1850,
p. 210; LE
JOLIS,
Alg. mar.
Cherb.,
1880,
p.
103,
pi.
3,
fig.
1
2; BERTHOLD, Bangia-
cea3,
1882,
p.
25.
The
plant
is,
as
mentioned
and
figured
by
ROSENVINGE,
fastened to the substratum by the basal cell which forms an
irre-
gularly lobed
disc often with ramified
rhizines radiating from
it.
The length
of
the vegetative
cells
is
rather variable
;
most
often the length
is shorter than the breadth, but cells longer than
broad
occur.
The
cells contain a
starlike chromatophore with a
large pyrenoid and
a small nucleus not always easy to find
as it
is
often,
as
pointed
out
by
ROSENVINGE,
hidden
behind
the
chromatophore.
The reproductive
cells
are commonly somewhat
longer than
the breadth,
the sporangium was
of about the same
size
as the
sister
cell or somewhat smaller.
It has
been gathered
in the months December
March and
was in
fruit
it that time.
It
occurs
epiphytically upon
larger
algse,
e.
g.
Sargassum,
Acanthophora
etc. and seems
to be rather common.
Geogr. Distrib.
Atlantic coast of Europe and North America, Medi-
terranean Sea, Maroc, West coast
of North America
etc.
Erythrocladia Kosenv.
1.
Erythrocladia
subintegra Rosenv.
ROSENVINGE,
L. KOLDERUP, The
marine Algae
of Denmark,
Part
I,
Kobenhavn 1909,
p.
73.
This plant was
found epiphytic
(Fig. 3 d)
l
)
upon
specimens
of Chaetomorpha and Cladophora upon which it forms small roundish
*) In
contradiction
to
the
statement
of ROSENVINGE, HOWE
(in "The
marine Algse
of Peru",
p.
82)
is of
the opinion
that
it
is
ordinarily
immersed in the
wall
of
the
host and that
it
is "endophytic
rather
than epiphytic".
8
or more
irregularly shaped discs up to 300
/j.
in diameter or even
more.
The young specimens have a nearly circular or somewhat
undulate continuous margin
(Fig.
3, a and
b),
in
older specimens
it
is more irregular and the extremeties
of the filaments become
Fig.
3.
Erythrocladia subintegra Rosenv.
a,
b, young
plants
seen from above,
c,
older
plants with
more
irregular
margin,
d, transverse section
of the
thallus.
(About 700
: 1).
more
or
less
free
(Fig.
3
c).
It
has
marginal
growth
and,
as
pointed out by ROSENVINGE, the
cells
are dichotomously divided
but
the
bifurcation
is most
often not
quite
equal,
the
one
cell
being larger than the other.
Near the margin the cells are often
linear-oblong or forked, in the middle
shorter, oblong,
or
of more irregular
shape.
The diameter of the cells is mostly
3
4 n but
it
is very variable and so
also the
length which often reaches
up
to
16 u
or more.
The
chromatophore
was
not
clearly
visible
but
it
seems
to
be
Fig.
4.
Erythrocladia subintegra
parietal with a pyrenoid in the middle
Rosenv.
Part of
a plant
seen
of the
cell.
from
above.
In
some
of
the
rr-,1
/T-.-
\
cells sporangia are cut
off.
The
sporangia
(Fig.
4)
are
as
(About 700
: 1).
said
by ROSENVINGE
cut
off
in
the
ends
of the vegetative
cells through
a somewhat curved
wall
;
they
are
of
variable
shape
and
size,
mostly roundish
orbicular and about
3
4// broad.
In referring
this plant
to
the genus Erythrocladia
I
confess
that
it
is not without doubt.
According to ROSENVINGE
1. c.
p. 72
9
the thallus
of
this genus
"consists
of mutually separate filaments
which only at a later stage
are partly confluent"
;
this corresponds
with Erythrocladia
irregularis
but how
far
it does with Erythro-
cladia subintegra seems more doubtful.
Rosenvinge has not found
young
specimens
of
his
plant
but
such
occurred
often
in my
material and
as pointed out
above the young specimens
have
a
continuous margin with no
free ends;
in the
older specimens, on
the other hand, with more irregular margin free ends are present.
These
older
specimens
agree very well
with the
figures
13 and
14
of
ROSENVINGE
and
also
with
specimens
in
a
preparation
which he has most
kindly allowed me
to examine.
Dr. ROSEN-
VINGE
discusses
the
possibility as to how
far
this
species ought
to be
referred
to the genus Erythropeltis Schmitz l
] but as pointed
out by him such a comparison
is
difficult to undertake
as Ery-
thropeltis
is
imperfectly
known.
In my
opinion
this
genus
of
SCHMITZ
is
very problematic
as
is
also pointed out by HOWE 2
):
"SCHMITZ,
in
proposing
the new
generic name
Erythropeltis
for
Erythrotrichia discigera Berthold (which he
cites
as the monotype
of
his new genus without any pro parte
reservations), omits any
reference
to
the
erect
filaments described
and
figured by BER-
THOLD".
Erect filaments have not been found
neither
in ROSEN-
VINGE'S nor in my plant.
On account
of these
facts
it seems to
me
not
impossible that this
species ougth
to
be
regarded
as a
representative
for a new genus.
Yet
I want to point out that my plant seems to show much
likeness to the
discs found
in the newly
described Erythrotrichia
polymorpha Howe 3
)
and
especially
to
those
forms
found
upon
Chsetomorpha
cartilaginea and Cladophora fascicularis in which the
erect
filaments
often
are
wanting.
If we
compare my
figures
(Fig. 3 a and
b) with
e. g.
figs. 5,
7 and
9
of HOWE
it cannot be
denied that the
similarity is striking,
But the cells and sporangia
are larger
in HOWE'S
plant,
the
disc
is
distromatic in the middle
and
erect filaments
are
also present.
St. Thomas:
In the Harbour, St. Croix:
Northside Estate.
Geogr. Distrib.
Danish waters.
Most probably widely spread.
)
In ENGLER & PRANTL, "Nat. Pflanzenfam."
I, Abt.
2,
p. 313,
1896.
*) HOWE, M. A.,
1.
c.,
p. 80.
3
) HOWE, M. A.,
1.
c.,
p. 77.
10
Subfam.
3.
Bangieae.
Bangiopsis Schniitz.
1.
Bangiopsis subsimplex (Mont.) Schmitz.
SCHMITZ in Engler und Prantl,
Natiirl. Pflanzenfam.,
1.
Teil,
2. Abt.,
p.
314.
Compsopogon subsimplex Montagne in Annales scienc. nat., Bot.,
Ill 6 ser.,
t.
14,
1850,
p.
299.
When young
the
plant
is
filamentous composed
of a single
row
of
cells.
These
in
the
young
filaments
are
disc-shaped
(Fig.
5
c),
their
length
being much shorter than
the breadth,
often only
a
fourth
in
the
newly
divided
cells.
They are
divided
by
horizontal
walls
and
all
cells
are
capable of division. The
diameter
of
the
fila-
ments
is
about
35
/*.
The
base
of
the
plant
consists
of
an
enlarge-
ment
of the lowermost
end
of
the
basal
cell,
forming
in
this way
a
small
disc by means
of
which the plant is faste-
ned
to
the substratum
(Fig.
5 h).
I
have
not
seen any rhizoids grow-
ing out from the lower-
most cells
as
is the case
in Bangia.
In
the
somewhat
older filaments the
cells
now and then
begin
to
be
divided
also
by
longitudinal
or more or
less oblique
walls.
This
Fig. 5.
Bangiopsis subsimplex (Mont.) Schmitz.
a, part
of a filament which begin to be rami-
fied,
b, part of a ramified thallus.
c, filament
composed
of
a
single row
of
cells
showing
cell-division, in the upper end one cell divided
by an oblique wall,
d,
e,
f, g,
transverse
sec-
tions
of
filaments
consisting
of
a
single
to
many
cells,
h,
base
of
a
plant,
(a and
b
about 150
: 1, ch, 200
:
1).
division
of
the
cells
is
rather irregular;
in some
plants
nearly
the whole
filaments
are
divided,
in other we find parts of the filaments divided
into many
11
cells and between these there
are thinner parts
still consisting of
a
single row
of
cells
(Fig. 5 a).
Figs. 5 d,
e,
/, g show transverse sections of filaments
in differ-
ent stages of development;
fig. 5 d
is of a filament
still consisting
of a
single row of
cells,
in
fig. 5 e we find two
cells and
in
fig. 5 /
and g
several.
As the figures show the cells
lie
scattered without
order in the whole filament.
In
this my plant
differs
essentially
from the description
of SCHMITZ
(1.
c.) where
the
thallus
is
said
to be
:
"der ganzen Lange nach rohrig hohl, mit gallertgefulltem
Hohlraume".
Now and then
especially from the thicker parts
of
the
fila-
ments branches grow out;
these are commonly short, proliferation-
like,
consisting
of
a
single
row
of
cells
(Fig. 5 b,
Fig. 6)
;
only
rarely
I have found them longer
and more like the main filaments.
Each
cell contains a
starlike
red-violet
chromatophore
in the
middle
of which a large pyrenoid
is present
(Fig.
6).
In
some
filaments
all
or
nearly
all
cells
were
emptied,
the few remaining cells were nearly
spherical and with a
granulated
contents.
I
take these
cells
for
the gonidia.
I have not succeeded
in finding
other
kind
of
organs
of propagation.
While my
plant
seems
to
agree
quite well with
the
description
of MONTAGNE
it
differs
as
pointed
out
above
from
that
of SCHMITZ'S by
its
solid
thallus.
MONTAGNE
referred
the
plant
to
the
genus Compsopogon,
while
SCHMITZ
created
for
it
the
genus
Bangiopsis.
It
comes
surely
near
to Bangia
but
differs
essentially
from
this
genus by
the
want
of
rhizines
at
the
base
and by
the common
presence
of
proliferations and
especially by the
rather irregular
cell-division,
the
cells
in Bangia being divided by radial walls and these
as a
result are generally wedge-shaped.
The
plant
has been
found
only
once
growing upon
a buoy
in
the
harbour of Christianssted, St. Croix.
Geogr. Distrib.
Guiana.
Fig. 6. Bangiopsis subsimplex (Mont.)
Schmitz.
Part of a thallus showing
cells with chromatophores and pyre-
noids.
(About 250
: 1).
12
B.
Florideae.
I.
Nemalionales.
1.
Helminthocladiacece.
Subfam.
1.
Chantransieae.
Acrochaetium Mgl.
After an exhaustive enquiry
as to
the
correct
generic name
for the plants hitherto usually grouped under Chantransia
I have
come to the
conclusion,
in agreement with the opinion, amongst
others, of J. AoARDH 1
), BATTERS 2
) and quite recently M. A. HowE 3
)
that we must adopt NAGELI'S name
Acrochaetium*).
I
will shortly give my reasons
for
this.
The genus Chantransia was originally created by DE CANDOLLE 5
)
but,
as
pointed
out by TnuRET 6
),
his
genus
includes
forms
of
genera as
different
as Lemanea, Batrachospermum, Cladophora and
Oedogonium
and
has
therefore
nothing
to
do
with
the
genus
Chantransia as now understood.
It was
first
FRIES') who
in 1825
reorganized
it more pre-
cisely
giving
as
types
of
the
genus
the two
freshwater
forms
Conferva Hermanni and
Conferva chalybsea Roth.
But before
this BORY S
) had already referred these plants to
his new
genus
Audouinella.
From
this
fact
alone
the
genus
Chantransia Fries ought to be regarded
as a synonym when
the
priority
is
strictly
followed.
But
the
position
of
this
genus
became yet more untenable when
it was discovered by SiRODOT 9
)
*) AGARDH,
J., Analecta Algologica, Lundae 1892,
p.
45.
2
) BATTERS,
E. A. L., A Catalogue
of the British marine AlgaB (Journ. of
Bot., Supplem.
1902,
p.
58).
3
) HOWE, M.
A., The Algse
of Peru (Memoirs
of
the Torrey Bot.
Club,
vol. XV, New York 1914,
p.
63).
4
) NAGELI,
Beitrage
zur Morphologic
und
Systematik
der
Ceramiacea?.
(Sitzungsb.
Konigl.
Bayer. Akademie der Wissensch.,
1861,
p. 402).
5
) LAMARCK ET DE CANDOLLE,
Flore Francaise,
t.
II,
1805,
p. 49.
6
) THURET
in LE
JOLIS,
Liste des Algues de Cherbourg,
1864,
p.
104.
7
) FRIES,
E., Systema orbis vegetabilis, Pars
I,
p. 338, Lundse
1825.
8
) BORY
DE
SAINT-VINCENT
in
"Dictionnaire
classique
d'histoire
natu-
relle",
t.
3, Paris
1823,
p. 340.
') SIRODOT,
S., Les Batrachospermes.
Paris
1884.
13
and later by other investigators
x
) that the freshwater Chantransise
were only stages
in development
of Batrachospermum
etc. 2
).
NAGELI
published
his
genus
Acrochsetium
in
1861.
It was
based
upon
several
marine
forms known
at
that
time.
But
in
those days
the
freshwater Chantransia
were considered
as
inde-
pendent species,
and
these
are,
as
is well known,
so much
like
the
marine ones that NAGELI ought to have
referred the marine
species
to
this genus
as THURET did some few years
after.
Had
NAGELI done
so, we should not perhaps have been obliged to give
up
this
old
generic name.
Yet
it
should
be
born
in
mind
that
ScHMiTz 3
)
in
1889
reformed
the
genus
Chantransia
in
a somewhat
different
sense
to THURET namely without including the
freshwater Chantransia
and
in
his
sense therefore the genus equals Acrochsetium.
Owing
to
these
facts
it
seems
to me
necessary
to
adopt
NAGELI'S name.
In connection
with
this
I
will
transcribe BAT-
TERS' conclusion
as to
this
question.
In his paper quoted above
he writes
p. 58: "Under these circumstances
it seems
to me that
either the name Audouinella must be substituted
for Chantransia
as that genus was understood by THURET
(i.
e.
to
include both
freshwater forms,
like
C.
chalybea and C. Hermanni, and marine,
like
C.
corymbifera,
C.
efflorescens,
and
C.
microscopied),
or,
as
seems
preferable,
to
preserve
the
former
name
as
that
of
a
doubtful genus
of freshwater
algae, and
to adopt NAGELI'S genus
Acrochsetium for the reception of the well-understood marine forms".
In
1904 BoRNET 4
)
proposed
to
separate
the
species
with
sexual reproduction
from
those bearing only
sporangia
the
first
ones
to be kept
in the genus Chantransia the others to be
refer-
red
to
the
genus Acrochsetium.
I
quite agree with
ROSENVINGE
that
this
distinction
seems
very
artificial
and
in
the
following
survey
of the
species found
in
the
Danish West
Indies
I
follow
him and
refer
all the
species to the same genus.
*) Comp. DE TONI, Sylloge Alg.,
vol. IV, Sectio
IV,
p. 1863, the
note.
2
) Here
I may
call attention
to the fact that BRAND
(in his paper: Uber
die Siisswasserformen von Chantransia
(D. C.) Schmitz
einschliesslich
Pseudochantransia Brand,
"Hedwigia"
vol.
49)
has pointed out that
besides
the Chantransia-lik.e
forms
of Batrachospermum
etc.
there
are
also some independent species of Chantransia and among these Ch. Her-
manni.
This certainly needs further investigation.
3
) SCHMITZ, FR., Systematische Ubersicht der bisher bekannten Gattungen
der Florideen ("Flora",
1889).
4
) BORNET,
E., Deux Chantransia corymbifera Thuret.
Acrochastium
et
Chantransia
(Bull.
Soc.
bot. de France,
T. 51,
Paris
1904).
14
In
this connection, however,
I may remark that
in nearly
all
the species mentioned below I have looked in vain for sexual organs
;
only
in a
single
species, Acroch.
Sargassi, were they found.
Neither did tetrasporangia occur in the West
Indian
species
collected by me;
on the other hand
I have previously described
a species Acrochsstium (Chantransid) bisporum in which sporangia
divided by
a cross
wall
into two
spores
were common and
in
another
species,
Acrochaetium
occidentals,
described
below some
few sporangia divided in the same way were met with.
In the above-mentioned paper by BORNET the eminent phy-
cologist has pointed out
that
the development and
structure
of
the basal part
of
the
thallus
is
of
great
systematic value
in
a
genus consisting of
such
small plants and,
as to the vegetative
and reproductive parts
of the
thallus, often
so very
similar.
In
his
excellent
treatment
of
the
Danish
species ROSENVINGE
also
has
largely
based
his
differentiation
and
classification
of
the
species on the method
of development
of the basal portion.
In
the West
Indian
material
likewise
it
has
been
evident
that
excellent
characters may be found
in the base of the thallus
and
I
have
succeeded
in
finding
not
only
most
of
the
types
mentioned by ROSENVINGE
but
also others coming near
to some
mentioned by
BORNET.
It
has,
however,
not
always
been
an
easy matter to
follow the development of the germinating spore.
When several
species grow together
this
is most often impossible ;
upon the leaves
of
an
old Sargassum vulgare was found
at least
six
different
species
and
here
it was very
difficult
to
clear up
the structure
of
the
basal
part,
and
its development
from the
germinating spore was
quite out
of the
question.
Of one species
mentioned below
I have only succeded in finding a single specimen
and have not been able with certainty to
state the
structure
of
the base
; but
as the plant had
a very characteristic appearance
I think
it
is
entitled
to a
description.
When speaking
of
the
basal part
I wish
also
to
point
out
that there
are many connecting
links from the epiphytic to the
endophytic
species.
In
Acrochastium
crassipes
the
lowermost
part
is, when growing upon
a
plant
of
soft
surface,
often some-
what immersed
; on the other hand when growing upon the spines
of Centroceras
it seems not immersed at
all.
Upon
Avrainvillea
nigricans
was
found
an
Acrochaetium
(A. Avrainvillese) whose base, composed of short creeping filaments,
was
fixed
to
filaments
rather
deeply
sunk
in
the
tissue
of
the
host
plant.
The
tissue
of
A.
nigricans
is very
loose and open
15
and
the
erect
filaments
of
the
Acrochsetium
have
not
much
difficulty in immerging from
it.
From
this stage of endophytism,
if such
it ought
be
called,
there
is an even
transition to those
species
(as Acroch&tium occidentals and Acr. comptum)
fixed to the
assimilating
filaments
of Liagora.
The
space
between
the
fila-
ments of the
species belonging to this genus is filled with mucilage
and
also
with more or
less
of
a chalk incrustation.
The
basal
filaments
of
the
above
mentioned
Acrochsetium
species
creep
epiphytically upon the filaments of the host
plant, but they are
on the
other
hand
immersed
in the
mucilage.
Quite immersed
in
this mucilage
is Acrochsetium Liagorse.
In other
species
again the endophytic filaments are
able to
penetrate more
or
less
into the
cellular tissue
of the host plant.
Here
also
graditions may
be
observed.
In some
species
e.
g.
Acrochsetium robustum,
unipes and
others only short endophytic
processes are
present.
In Acrochsetium hormorhizum the basal part
is immersed in the thick wall of the host plant.
Acrochsetium repens
has endophytic filaments creeping extensively
in the tissue of the
host plant sending up here and there erect
free
filaments.
Further
as
pointed out by KYLIN and
later by ROSENVINGE
the shape of the chromatophore
is of great systematic importance.
Referring for
details to ROSENVINGE'S
description
I will here only
mention
that by
far
the
greatest number
of
the West
Indian
species have a parietal more or
less lobed chromatophore with a
lateral excentric pyrenoid protruding more or
less
into the lumen
of
the
cell.
In
other
species
a
stellate
chromatophore with
a
central pyrenoid
is
found.
The
following
classification of the
species
is based essentially
upon the
different development of the basal part, next upon the
shape
of the chromatophore and other characters.
Key
to the West Indian
species
of Acrochaetium.
A. Epiphytes.
a. A
single undivided basal
cell.
1. With sex-organs, chromatophore
parietal
1.
A.
Sargassi.
2. Without
sex-organs, chromatophore
stellate
....
2.
A.
crassipes.
b. The germinating spore
is divided
into two
cells
.
.
.
3.
A. pulchellum.
c.
Basal layer
multicellular, composed
of creeping
fila-
ments
fusing more
or
less together.
16
1.
Erect filaments about 56^ thick.
a. Sporangia
sessile or pedicellate,
fusiform
....
4.
A.
netrocarpum.
/9. Sporangia
sessile
or
pedicellate
or several
to-
gether upon
short branchlets,
oblong-linear
.
.
5.
A.
gracile.
Y.
Branchlets mostly opposite with mostly several
sporangia
6.
.4. globosum.
2.
Erect filaments about
8
10
(J.
thick.
a.
Cells proportionally short, mostly barrel-shaped,
hairs present
7.
A.
Sancti Thomse.
/9.
Cells
cylindric,
hairs wanting.
aa. Sporangia seriate, mostly
sessile, sometimes
pedicellate
8.
A.
seriatum.
bb. Sporangia
mostly
placed 12 upon bran-
chlets
9.
A. flexuosum.
B. The base
of the plant partly endophytic.
a. Germinating spore persistent at the base of the plant.
a. Spore
with
a
single
endophytic,
obovate
or
subclavate, descending process ....
10.
A.
unipes.
ft. Spore with a cuneate process and, sometimes, with
short epiphytic horizontal branches
11.
A. opetigenum.
b. Epiphytic basal disc with endophytic process
12. A.robustum.
c. Epiphytic and endophytic filaments ...
13.
A. bisporum.
C. The whole base
of the plant endophytic.
a. The germinating spore persistent and easily recogniz-
able.
1. The spore remains undivided
14.
A.
Occidentale.
2. The germinating spore
is divided into two cells
.
.
15.
A.
comptutn.
b The
original spore not recognizable.
1. Base composed of more
or
less horizontal creeping
filaments.
a. The base immersed
in
the
loose
tissue
of
the
host plant
16.
A.
Avrainvilless.
/?. The
base immersed
in
the
thick wall
of
the
host plant; endophytic filaments moniliform
.
.
17.
A. hormorhizum.
f. The endophytic filaments immersed
in the wall
and between the cells of the host
.
.
18.
A. Hypneae.
d. The endophytic filaments widely spread
in the
tissue
of the host
19.
A.
repens.
17
2. A multicellular vertical basal layer
20. A. phacelorhizum.
D. The whole plant immersed in the host plant
.
21.
A. Liagorse.
In addition
is described below .4. ernothrix the base
of which
I have not succeeded
in seeing
clearly.
1.
Acrochsetium
Sargassi nov.
spec.
Thallus usque ad
700 p
altus.
E
cellula basali, discum par-
vum formante,
filum erectum,
a basi ramosum,
egreditur.
Kami
sparsi aut secundati aut oppositi,
simplices aut ramosi,
ad apicem versus attenuati,
in pseudopila sa3pe producti, ex cellu-
lis in parte
inferiori
thalli
5,5 p
latis,
9
18^
longis,
in
superiori
parte
2
3/j.
latis, 30
40^
longis compositi.
Ghromatophorum parietale, pyrenoide
laterali instructum.
Sporangia sparsa aut pauca secundata,
in ramulis
sa?pe bina
praesentia,
sessilia aut
pedicellata,
obovata,
10 p
longa,
7//
lata.
Antheridia
in
ramulis
opposita
aut
plus
minus
irregulariter
aggregata,
globularia,
ca.
2
//
lata;
carpogonia
lageniformia,
sessilia.
This
plant
reaches
a
length
of
up
to
600
700 /*.
The
base
(Figs. 7 and 8 a)
consists of a
flat disc (about 20^ diameter)
formed
by
the
original
spore
and
apparently
in
a
similar
way to
that
found
in Acrochastium
(Chcmtmnsid)
microscopicum
Nsegl.
var.
collopoda ROSENVINGE,
described
and
figured by Ro-
SENVINGE
in "Deuxieme Memoire sur
les Algues
mar. du Green-
land" (Meddelelser om Granland, XX,
p. 412).
By means of this
small
disc
the plant
is
fixed firmly to the host plant
(old leaves
of Sargassum vulgare).
From
this disc
is given
off a
single filament which immedia-
tely begins to branch
(Fig.
7).
The
cells
in
the lowermost part
of the filaments are short and have thick walls
; they are about
9//
long
and
5,5^
broad,
in
vigorous
plants
up
to
8// broad.
Higher up the
cells grow longer, up to about 18,, tapering at the
same time,
and the filaments end with long, thin nearly colour-
less,
hairlike
prolongations
which
soon
die away
;
in
these
the
cells
are only
2
3 p.
broad
while
their
length
is about 30
40 u
or
more.
ROSENVINGE
also
found such discoloured prolongations
in
several
species and compared them with the
hair-like organs
in the
Phseophycese.
2
18
The
filaments
are
as
a
rule
very
stiff
and
straight
and
arise
from
the
principal
filaments,
often
serially,
sometimes
Fig.
7.
Acrochsetium Sargassi nov.
spec.
Habit of a plant with monosporangia and antheridia.
(About 180
: 1).
scattered,
and now and
then
opposite
(Fig.
7).
The
branches
are
similarly ramified and
run out into long
hair-like
organs.
19
The chromatophore
is usually slightly developed
(Figs. 9 and
10);
it
is
parietal
often with some long
irregularly
shaped pro-
longations
;
in some
of the
cells
it often consists only
of a small
portion surrounding the
pyrenoid
and
lying
at
the wall
of the
cell.
The
sporangia
are
found either at the base
of
the
filaments
upon
their
upper
side
some-
times
solitary,
some-
times two
or
three
to-
gether,
or
they
may
occur upon
short bran-
chlets given off from the
principal filaments. They
are
mostly
pedicellate
but
sessile
ones
also
occur.
The
sporangia
Fig
8
Acroeha!tiwn Sargassi nov
. spec .
are
oval-obovate
(Fig.
a, plant with sporangia,
b, part of a filament
8 h
QV
thpir
lono-Hi
i
with sporangia,
c, part of a plant with carpo-
>
'
gonia.
(a, about 100
: 1,
b, 500
: 1,
c, 400
: 1).
about 10^, their breadth
about
7
fj..
This
is the only West Indian
species in which sexual organs
were
found.
Specimens with antheridia were seen several times
(Fig.
7).
The
antheridia
occurred
in
pairs
along both
sides
of
the small
fertile branch-
lets
(Fig.
10)
but
were now
and then more
irregularly arranged.
For
a
long
time
I
searched
vainly
for
the carpogonia and
finally
I succeded in find-
ing a specimen
in which some few carpogonia
undoubtedly were
present.
As Fig. 8 c shows
Fig.
9.
Acrochsetium
they are bottle-shaped having nearly the same
Sargassi
nov.
spec.
Part
of
the
thallus
form as
in
other
species.
No
later stages of
with sporangia.
The
carpogonia were found.
nethermost has been
1
.
emptied
and
a new
This
plant
seems
to come very near
to
one
is
growing
out
Acrochsetium Dufourii Collins and
I have been
again, (about 600: 1).
.
,
.
.
,
,
in great
doubt how
far that plant
is
indeed
only
a young
state
of my
species.
But
after having examined
the
original
material
of Acroch.
Dufourii,
distributed
in "Phyc.
Bor.-Am.", No. 1594
I think
it
is
not.
2*
20
A general
difference must
be
pointed
out
in
the
fact that
Acrochset. Dufourii seems
to be somewhat smaller in
all parts of
its
thallus.
The base
in both plants appears to be very alike
; in both it
is
a somewhat
flat,
upwards convex,
below
nearly
plane
disc,
formed
by
secretion
of
the
basal
cell;
it
is
smaller
in
Acr.
Dufourii than that
found
in my plant,
but
in one specimen
it
reached a diameter
of about
14//.
In
Acr. Dufourii
the
erect
filaments are about 4
5// broad,
in my
plant
the
filaments
at
their
base
are
mostly 5
6
but specimens occur in which the filaments
are 8^
thick.
But
while,
and
this
is
the
most
essen-
tial
difference,
the
plant
of Mr. COLLINS
does
not
Fig. 10. Aero-
taper towards
its summit the filaments
in my plant
chsetwm
Sar-
taper
very much
and
run
out
in
thin
nearly
gassi
nov.
J
.
.
.
J
spec.
Branch
colourless
hair-like prolongations.
This
is not men-
with
branch-
tioned
in the description
of COLLINS and
I have not
lets bearing
.
antheridia.
been
able
to
find
any
trace
of
this
in
the
dried
(About
specimen
in "Phycotheca".
Besides,
as
is
evident
from the above
description, my plant
is much more
branched
and
generally more
developed
(e. g. with
sex
organs)
than Acr.
Dufourii.
This
species
occurred
together with
several
other upon old
leaves
of Sargassum vulgare.
St. Thomas:
The Harbour.
2.
Acrochaetium
crassipes B0rgs.
BORGESEN,
F., Some new
or
little known West Indian
Floridese,
I.
(Botanisk
Tidsskrift,
vol. 30,
1909,
p.
1).
var.
typica nov. var.
B0RGESEN,
F.,
1.
C.
My previous description
of
this
plant was
based upon
few
specimens only
; now by renewed
efforts
I
have
been fortunate
enough to find
it
in other collections and
this enables me to give
some additions to my former
description.
The basal
cell
is
subcylindric-barrelshaped with
thick walls
(Fig.ll^4,j5)
;
in my former description
I
said that
it was fastened
to
the
surface
of
the
host
plant by means
of
a
rather
thick
layer
of cementing substance and
this
is
also
the
case where
it
is growing
e.
g.
on
the
spines
of
Centroceras as shown
in
the
fig. 11 A and B,
but when found upon a more
soft
substratum
e.
g.
upon Hypnea
it sometimes,
at any
rate,
is
somewhat im-
21
- ^crochxtium crassipes
var.
typica.
A
and B,
two
plants
growing
on
Cen-
c
*'
pi *
.
mersed with the basal part
in the wall
of the
host
plant,
in
agreement
with
M. A. HOWE'S description of Acrochsstium
catenulatum 1
).
The basal
cell bears
as a
rule one
or two erect filaments which most often
are more or
less curved and decumbent
and
graduallly
taper
towards
their
summits
flip*
basal
ppll
hpino-
thp
jS '
tne
thickest
of
all.
Hairs seldom occur
; most of the plants
are quite destitute of them. Where they
with monosporangia (300
: 1).
are present they are always to be found
at the
tips
of the filaments (Fig. 11 B},
The chromatophore
is
stellate with
a
central
pyrenoid.
In
most
of the
cells plenty of starch
is present and the contents of
the
cells then have a quite homogenous
appearance
;
but when
boiled and
coloured
e.
g. by means
of haam-
alun the
stellate chromatophore
is easily seen.
var.
lofigiseta nov. var.
Upon specimens of Chsstomorpha antennina
from
the
harbour
of
St.
Thomas
and
on
Chsetomorpha
brachygona
from
Christianssted
was
found
abundantly
a
small
Acrochsetium
which shows
so much likeness to Acrochsetium
crassipes that
I have no doubt
in
referring
it
to
this species from which
it essentially differs
by the usual presence
of long
hairs.
The
basal
cell originating from
the
ger-
minating spore
is, as is the case
in var. typica,
the
largest
of the whole plant (Fig.
12), being
8
10^
in diameter.
It
is
fixed
to
the
host
plant by means
of
a
ring of
cementing sub-
stance and,
so far as
I have been able to
see,
it
is
also
often somewhat
immersed
in
the
wall
of
the
host
(Fig. 12,
13
e).
From
the
basal
cell
arise
a
single
or
2
3
suberect
branches,
the
cells
of which grow
gradually
thinner and
at the same time longer towards
Fig. 12.
Acrochselium
crassipes
Borgs.
var.
longiseta
nov.
var.
Plant
with
a
single
sporangium and hairs,
in the
cells
the
stel-
late
chromatophore
with the central pyre-
noid.
(about 800
: 1).
x
) M. A. HOWE, The marine Algae of Peru ("Memoirs
of
the Torrey Bo-
tanical Club",
vol. XV,
1914,
p. 84).
22
the summit where their diameter
is only about
4
5^ while the
length
of the
cell
is about 6
7^.
The basal
cell and the lower-
most
cells
in
the
filaments
are
about
as
long
as broad,
often
even
a
little shorter than broad.
The principal filaments are
as in the
var. typica
mostly very
curved
(Fig. 13 a,
c)
;
along
the
upward
side
of
the
filaments
all the
cells may bear sporangia,
or in the more vigorous plants
short
branchlets
;
more
rarely
some
of
the
cells
are provided
with branches on the opposite side
(Fig. 13 c).
The
cells
contain
a
stellate
chromatophore
with
a
central
pyrenoid
(Fig.
12)
quite
in
ac-
cordance with that found
in the
var.
typica.
At the ends of the filaments
long hyaline hairs occur (Figs. 12,
13), these
are about
1
2// thick
and reach a length of about 50 ^.
The
sporangia
are
always
monosporous
;
they
are
oval-
obovate,
about
5 ^
broad
and
Fig. 13. Acrochaetiutncrassipes~B0rgs.
6
7^
long.
They
are
mostly
var. longiseta nov. var.
a, b,
c, habit
opoojlp
hnt somptimps
also
nprli-
of plants,
d, a young plant,
e, base
sessile >
Dut sometime,,
also pe
of
a
plant
showing
the
immersed
cellate
or
placed
upon
short
nethermost
part,
(a,
b
c
about
branch iet s
; now and
then such
2o()
: 1
;
a,
e, about 800:1).
branchlets
have
two
sporangia.
The length of the larger specimens without hairs is about 60 p.
This species seems to be nearly related to Acrochastium (Chan-
transia)
moniliforme
Rosenvinge
and
Acrochsetium
catenulatum
Howe.
From the
first mentioned
species
it
differs
essentially
in
its smaller
size
in every respect, and by the proportionally larger
basal
cell.
And Acrocheelium
catenulatum
differs from our
plant
among
other things by
its
larger
size,
want
of
hairs
and
ap-
parently different chromatophore.
This species has been found upon different host plants, namely,
Hypnea,
Centroceras,
Bryopsis,
Chsetomorpha,
Cladophora
etc.
It
seems to be a common
species especially
in more sheltered places.
Var.
typica has been found at St. Thomas:
in
the Harbour and
in
Magens Bay , at S t. J a n
: in Cruz Bay and at S t. C r o i x
: near Christianssted.
Var.
longiseta.
St. Thomas:
in the Harbour and
at Water Island;
St. Groix:
at Christianssted.
23
3.
Acrochsetium pulchellum nov.
spec.
Thallus minutus, pulvinatus.
Pars
basalis
e
filis
repentibus
ramosis,
in parte
centrali sensim confluentibus, composita. Spora
germinans
in duas
cellulas
fere a^quales
divisa
est, quarum utra-
que filum ramosum repens procreat.
Cellulse
in parte basali
irregulares,
breves,
7
10^
longae
et
5
Qfji
Iata3.
Ex
his
cellulis
fila
erecta brevia,
1
3 raro plures
cellulas continentia, ca. 24
/j.
alta, egrediuntur
;
cellule 5
6// Iata3,
diametro ! 1
/ 2
2-plo longiores, chromatophorum stellare pyrenoide
centrali instructum continentes.
Pili hyalini
terminales,
ca.
100
//
longi,
2
3 p
lati,
numerosi.
Sporangia in
filis erectis terminalia,
raro
in filamentis repentibus sessilia, ovata, 5
7
(j.
lata
et
9
10
fj.
longa.
Of the
species described by ROSENVINGE
the present plant seems
to come nearest to
ACT. (Chr.) humile;
in
its mode
of growth
and the structure
of
the
cells
it
also some-
what
resembles A. (C.) polyblastum Rosenv.
but the
erect filaments
are not
so
large.
In agreement with the above mentioned
species
the
germinating
spores
are
divided
Fig.
14.
Acroch&tium
into two nearly equal
cells
(Fig. 14)
;
in the
pulchellum
nov.
spec.
i
.
,
11
-i
Young plants in which
young plants these
cells are
easily
recogmz-
the original spores,
di-
able,
in
the older they
are most often
not.
vided
into
two
cells,
o -pp vpt
vi si hi p
From each of these
cells a creeping filament
(About 600
1).
is
given
off
in
opposite
directions
;
these
filaments soon begin to branch, the branches
in the middle fusing
more
or
less
together.
By this method
of growing a
relatively
large
disc may
be
formed
(Fig.
15).
The
cells
are rather
irre-
gularly
shaped
with more
or
less
sinuated
walls,
short,
about
5
6 n broad and
7
10 n
long.
From the
cells
in the basal layer short erect
filaments con-
sisting
of
1
3
seldom
more
cells
arise.
These
filaments
are
terminated by long hyaline hairs or they may bear the sporangia
(Fig.
15).
Hairs
also occur at the ends of the creeping filaments
but are soon pushed
aside.
The
hairs reach a length
of 100 p or
more and 2
3^ broad.
They
are,
as mentioned above, hyaline;
the young hairs are
richly provided with protoplasm.
The
chromatophore
is
stellate
with
a
central
pyrenoid
(Figs. 15 and
16).
24
The
erect filaments reach 24
/j. and occasionally higher
;
their
breadth
is about 5
6
/.
Fig.
15.
Acrochsetium pulchellum nov.
spec.
Plant with monosporangia of which someones are emptied
;
it creeps upon
Chsetomorpha.
(About 700
:
1).
The sporangia are mostly
terminally
placed upon
the
erect
filaments
; more rarely
sessile sporangia, placed immediately upon
the cells of the basal filaments are found.
The sporangia are ovate,
about 5
7 p. broad and
9
10 a
long.
This species has been
found
upon
Chsetomor-
pha antennina in a very
exposed place on rocky
coast.
St. Croix:
Northside.
4.
Acrochsetium
netro-
carpum nov. spec.
Thallus
caespitosus
ad
400 //
altus,
e
filis
repentibus et
filis erectis
numerosis compositus.
Fila repentia ramosa,
plus minus
confluentia ex
cellulis bre-
vibus
irregulariter formatis constructa.
Fig.
16.
Acrochsetium
pulchellum
nov.
spec.
Plant with hairs.
(About
700
: 1).
25
Fila erecta parce ramosa,
5
6^
lata,
cellulis diametro triplo vel 4 plo longioribus,
cylindricis, in parte superiori filorum cellulis
tenuioribus, 3
4// latis, chromatophorum,
ut
videtur,
parietale
pyrenoide
laterali
munitum continentibus.
Sporangia monospora, fusiformia apice
truncate,
sessilia
aut
pedicellata,
sparsa
aut
unilateraliter seriata, 4
5/* lata, 10
11^
longa.
This
small
species
was
found
upon
old
leaves
of Caiderpa
taxifolia.
Only
a
single
tuft was met with growing in com-
pany with Acrochsetium seriatum and other
small epiphytes.
It forms a dense low tuft up to about
400 it
high.
The
basal
part
consists
of
creeping
filaments
(Fig.
17 d)
fusing more
or
less
together but,
it would seem,
easily separ-
able.
The
cells
in
these
filaments
are
Fig.17. Acrocheetium netro-
rather short, often nearly isodiametric but
ca>'Pum nov. spec,
a,
b,
c,
J
parts
of
filaments
with
much irregular in shape.
From nearly all
sporangia,
d, base of the
of these
cells with the exception
of those P^ 11
,*;^
la '
3 nXX
1
'-,^*'
c>
4-r\()
*
J
"
ft
|il
)l
|
"
|
near
the
margin
erect
filaments
arise.
These
(Fig. 17 a) are multilaterally ramified but not much so,
and
taper somewhat
towards
the
upper
end
(Fig. 17
c).
They
consist
of
cylindric
cells about 18
20// long;
in the basal part
these
cells
are
about
5
6 p
broad
while
those
at
the summit are only
3
4//.
The shape of the chromatophore was not
clearly
visible,
so
far
as
I
have
been
able
to
see
it was
parietal with a
lateral pyrenoid
; the
last mentioned
was more
visible
in
the sporangia
(Fig.
18).
The
latter
have
a
very
characteristic
shape
(Figs. 176,
18)
;
they
are
fusiform
with a
truncate
lg
summit,
about
4
5 p
broad
and
10
11
fj.
long.
Acrochsetium
They
are
mostly
sessile
but
often
also
pedicellate.
netrocarpum
They occur more or
less
in a
series or may be more
nov. spec.
J
Filament with
scattered.
sporangia.
(About
800
: 1).
This species has only been found once namely at Chri-
stianssted, St. Croix.
26
5.
Acrochsetium
gracile nov.
spec.
Thallus csespitosus usque ad
1 mm.
altus
et
ultra.
Pars basalis e filis repentibus. epiphyticis, plus minus lateraliter
confluentibus composita.
Fila erecta,
simplicia aut paucis ramulis
Fig.
19.
Acrochsetium gracile nov.
spec.
a and
b, erect filaments with sporangia,
c, base of a plant.
(a and
b, about 150: 1;
c, 250: 1).
in
superiori
parte
instructa,
ramulos
sporangit'eros,
1
2
raro
plures
cellulas
continentes
gerentia,
ad
apicem
versus
leniter
attenuata
ex
cellulis
cylindricis
in
inferiori
parte
filorum
5,5 u
27
latis
10 p
longis,
in
superior!
fere
2
/j.
latis et 20
fj.
et ultra longis
composita. Chromatophorum parietale, pyrenoide laterali munitum.
Monosporangia
aut
sessilia
aut
pedicellata
aut
in
ramulis
posita oblonga,
14
16^
longa,
6
8/*
lata.
The
base
of
the
plant
(Fig. 19
c)
consists
of
creeping
epi-
phytic filaments which are mostly free or somewhat fused together.
The
cells
in the basal part are about
as long as broad
or a little
longer.
They are
5,5
fj. broad.
From the cells
in
this disc erect filaments arise.
At the base
these
filaments
(Fig. 19 a, b)
are about
5,5// thick;
they
taper
slowly
towards
the
summits
and often
end with
long
hair-like
prolongations
in which the
cells
are
only
about
2// wide.
In the
lowest part
of the filaments the cells are about 10 p.
long,
in the
upper
end
on
the
other hand
they
often
reach
a
length
of about 20 // and more.
The
chromatophore
(Fig.
20)
is
parietal
with
irregular prolongations and contains a large pyrenoid
lying near the wall of the
cell and protruding deeply
into the
interior
of the
cell.
The filaments are not much branched, often not at
all
in the lowest part and bearing here for the most
F
-
9Q
part
only
short
branches
with
sporangia.
In the
chaetium
gm-
upper
part
the
filaments
give
off
multilaterally p^o^fda-
situated
branches,
mostly
only
a
few
and
these
ment with
branches
' are
as
mentioned above often terminated
sp/^out
a '
by thin
hair-like prolongations.
800
: 1).
The branchlets bearing the sporangia are mostly
multilaterally
placed upon the lower part
of the principal bran-
ches.
But uniseriated
branches
also
occur
especially
higher up
in the filaments.
Most
of the
branchlets
are
unicellular, bearing a
single
or
sometimes
two
sporangia,
but
two-celled
branchlets
are
also
common while
others with several
cells
are found more
rarely.
Sessile Sporangia
are
scarce
but they occur now and
then,
especially
in the upper end
of the
filaments.
The sporangia
(Figs. 19 a, b, Fig. 20) are
linear oblong, about
14
16 f*
long,
6
8,
broad.
This
species was found upon
old leaves
of Sargossum vulgare
growing here together with
several other
species.
Only found once in the Harbour of St. Thomas.
28
6.
Acrochsetium globosum nov.
spec.
Thallus caespitosus, globosus, ad
600/^
altus
;
in Chsetomorpha
antennina epiphyticus.
Fig.
21.
Acrochsetium globosum nov.
spec.
Part of a plant showing the basal creeping filaments from which
arise ere<
filaments with opposite sporangiferous branchlets.
(About
100: 1).
29
Discus
basalis
bene
evolutus,
unistratosus,
e
fills repentibus
ramosis, cellulis
fere isodiametricis, compositus.
Fila erecta nume-
rosa, parce ramosa, ad apicem versus attenuata et in pseudopila
producta;
in basi et media parte
5
6//,
in superiori parte 2
3//
crassa,
cellulis
inferioribus
c.
14^,
mediis
c.
30^,
superioribus
70 // vel plus longis. Ghromatophorum parietale, pyrenoide
laterali
instructum.
Ramuli
sporangiferi numerosi,
sparsi aut
saepe oppositi,
1
3,
rarius
plures,
cellulas continentes.
Sporangia
ovata.
7
8// lata
et
8
10
fj.
longa.
This
species was
found
upon Chastomorpha
antennina upon
which
it forms small dense nearly globular or semiglobular tufts.
The basal part (Fig. 21) of the plant consists
of creeping ramified filaments, more or less fusing
together and
forming
in
this way a
large
disc.
The cells in the disc are rather irregularly shaped,
about
as
long
as
broad
or a
little
longer
i.
e.
from
5 to
ll//
broad.
From
this
basal
part numerous
erect
fila-
ments grow up
; those
in the middle are nearly
straight,
those
in
the
periphery
are
bent
out-
wards
in view of space and
light.
At the base
the
erect filaments are about
5
6^
broad and
the length of the
cells about 14^.
Upwards the
length
of
the
cells
increases gradually reaching
in the middle of the filaments about 30^.
From
here
the
cells
not
only
grow
longer
but
the
filaments
also
taper towards
their
summits
in
such a way that the uppermost
cells only reach
a breadth of
2
3^ while the length of the cells
on
the
other
hand
is
often
more
than
70 //
(Fig.
21).
These thin unbranched prolongations
of the filaments are nearly or quite colourless and hairlike.
While
the lowermost
cells
in
the
filaments
taper a
little
at both ends
those higher up
in the filaments
are
cylindrical.
The
cells con-
tain a
slightly
developed
parietal
chromatophore
lying near the
upper end
of the
cell and
a
lateral pyrenoid
(Fig. 22).
The
erect filaments are multilaterally ramified but not much.
These
branches
contrast
distinctly
with
the
numerous
short
sporangiferous
branchlets.
Along
the
whole
length
of
the
fila-
ments
from
their base and up
to the beginning
of
the
hair-like
prolongations
nearly
all
the
cells
bear
either
a
single
or more
Fig. 22. Acrochee-
tiurn
globosum
nov.
spec.
Part
of a filament with
branchlets
bear-
ing sporangia
(some ones emp-
tied),
(about
600: 1).
30
often two
opposite
branchlets
(Fig.
21).
In
the
lowest part
of
the
plant
these
branchlets
consist
of
2
3,
rarely
more
cells,
higher up
of two,
then
of a
single
one
only;
at
the
top
some
few
sessile
sporangia may
occur.
The
cells
in
the
branchlets
are about
3/j. broad and
8//
long.
The sporangia are ovate about 7
8/* broad and 8
10 p long.
This species has been found
at
the very exposed coast
at Northside,
St. Croix.
7.
Acrochaetium
Sancti Thomas nov.
spec.
Thallus
sine
pilis usque ad 200
300
fj.
altus.
Discus
basalis
unistratus,
e
filis
re-
pentibus
plus
minus
lateraliter
confluenti-
bus,
compositus.
Fila
erecta
sim-
plicia
aut
parce
ra-
mosa,
e
cellulis
8
$
fj.
latis
et
16
18^
longis composita.
Chromatophorum
parietale,
pyrenoide,
ut
videtur,
centrali
instructum.
Pili longi hyalmi,
initio terminales, po-
stea
pseudolaterales,
adsunt.
Monosporangia
plerumque
sessilia
et
uniseriata,
interdum
pedicellata
et
oppo-
sita, solitaria vel bina
in uno
articulo,
ob-
ovata,
7
ft
lata
et
10
fj.
longa.
This
plant
was
found
together
with
.
several
other
species
ing.
if>.
Acrochaetium Sdncti Thomas
nov.
spec.
a,
b,
c,
three
parts
of
different
tufts showing
'
upon
old
leaves
ol
sporangia-bearing
filaments,
d,
e, bases of
Sargossum
vulgare
plants,
f, basal filaments seen from above.
(a, about 250:1, b,c, e, 130:1,
f, 250:1, d, 500:1).
forming
small
tufts.
31
The base (Fig. 23 d,
e, /)
consists of creeping filaments irregu-
larly ramified
and more
or
less
fusing
together
into a pseudo-
parenchymatous
disc.
From most
of
the
cells
in the creeping
filaments
erect ones
are given off.
These filaments are composed of
cells nearly twice
as
long
as
broad,
8
9//
thick and
16
18// long;
the
lowest
are nearly
cylindrical,
higher
up
in
the
filaments
the
cells are
more barrelshaped
being somewhat swollen
in
the middle
(Figs.
23 a,
24).
The
cells contain a
large
parietal chromatophore
with
long
lobes along the walls
of
the
cells
(Fig. 24) and with
a pyrenoid
lying near the middle
of
the
cell.
The shape
of
the chromato-
phore
seems
to
come
near
to
that
ROSENVINGE
found
in
A.
(C.) leptonema. The cells are mostly very rich in
starch
filling up
the greater part
of
the lumen
making
it
difficult
to
see
the
shape
of
the
chromatophore.
The filaments
are
mostly
slightly
ramified,
often not
at
all.
However, the more vigorously
developed filaments sometimes
give off branches
like themselves.
Short branchlets on
the other
hand are often present
(Fig. 23 a).
The
cells bear often long,
hyaline,
unicellu-
lar hairs
(Fig. 23 b,
c).
These
are
at first termi-
nal
on
the
end
of
the
filaments
but later on
they are
pushed
to
the
side by the
next new
cell
in the way described
for several
species by
KYLIN and ROSENVINGE, and the sympodial na-
ture
of the filaments was
clearly
visible
in
this
species.
The
hairs
are
thickest near
the
base,
here
about
4// broad,
tapering
towards
the
summit
where
their diameter
is only about
2 // long
; they reach a length
of about 200
300 /*.
The
hairs
are quite hyaline with
the
ex-
ception
of
the
uppermost
end
which
is
richly
provided
with
contents.
They seem to be rather early shed.
The
monosporangia
are
mostly
sessile,
arranged
in
series
upon
the
upper
end
of
each
cell
in
the
filaments,
some
are
pedicellate,
placed
upon
the
short
branchlets mentioned above
(Fig. 23 a).
The sporangia are oval-obovate
in shape (Fig. 24 a),
about
7
fj. broad and
10
/u.
long.
This species is certainly nearly related to Acroch&tium leptonema
Fig. 24. Acrochse-
tiumSancti Tkomse
nov. spec, a, sum-
mit of a filament
with
sporangia.
b, cells from lower
down
in
a
fila-
ment with
chro-
matophores
and
nuclei.
(About
500:
1).
32
Fig.
25.
Acrochsetium seriatum nov.
spec.
a, b, erect filaments with monosporangia.
c, base
of a small plant seen from above,
d, transverse
section of
the
base;
the lines
at both end are
the surface
of the host plant.
(a,
b, about 130:1;
c, 400:1;
d, 275:1).
Fig.
26.
Acrochsetium
Rosenv.; but to judge
from
the
figures
of
ROSENVINGE the habit
of
his plant
is
very
different
from
the
mine.
Further
the
filaments
in his plant
are only half as broad
as those
in my plant
and
the
sporangia
also
are
somewhat
smaller.
Only found once: St.
Thomas, The Harbour.
8.
AcrochaBtium
seriatum nov.
spec.
Thallus csespitosus
usque ad
1 mm
altus
e disco
basali in
fila-
mentis
hospitis
epi-
phytico et
filis erectis
ramosis constructus.
Discus basalis uni-
stratosus,e filis repen-
tibus
confluentibus,
cellulis
brevibus
fere
isodiametricis
irregu-
lariter
formatis com-
positus.
Fila erecta a
basi quoquoversum
ramosa
in
superior!
parte
secundatim
ra-
mosa,
ramis
principalibus
vix,
minoribus
plus minus ad apicem versus
attenuatis.
Cellula?
in parte
basali
ca.
22 p
Ionga3,
diametro ca. 8
10
/j.
lato,
in superior! parte
diametro
ca.
6
7//,
interdum 4^
lato.
et
ad
30 n
longae,
chromatophorum
parietale
lobatum,
pyrenoide
laterali
instructum
continentes.
Sporangia ovalia,
9
10
13 ^ longa et
seriatum.nov. spec. Base
6
9
lata,
sessilia
aut
interdum
pedicel-
of
a
plant
seen
from
,
'
.
.
.
above.
(About
400:1).
lata,
in
latere supenon ramorum plerum-
33
que secundatim ordinata,
rarius plus minus
sparsa.
This
species
is
an
epiphyte
especially
upon
Centroceras but
it
is also found upon
other
algae
e.
g.
Gracilaria,
Chsetomorpha,
Caulerpa
taxifolia etc.
It forms small more
or less dense
tufts from 500 // up to double
this height.
The basal part
(Fig. 25 c,
Fig. 26) con-
sists
of
short
irregularly
bent
creeping
filaments,
fusing
together
in
the
middle
into
a small
disc;
it
is composed
of short
rather thickwalled
cells.
From
the
cells
in
the
middle
of
this
disc several erect filaments gradually arise.
The filaments
consist
in
their lower
parts
of
cells
about
twice
as
long
as
broad,
namely 8
10//
broad
and
16
22^
long.
Upwards
the
filaments
taper
gradually,
reaching
near
the
summit
about
6
7/*,
while
the
length
of
the
cells
is
mostly
about the same throughout the whole
fila-
ment, but thinner branches occur in which
the
cells
are
only
about
4/*
broad
while
on the
other hand
the
length may
reach
up
to
30//.
The
erect filaments are branched often
from
quite near the base,
in the lower part
from
all
sides,
higher up
often quite
uni-
laterally
with
the
branches
lying
in
the
same plane;
the
branches
are again rami-
fied
in the same way
(Fig. 25 a)
; from this
the plant
often
gets
an
elegant
pectinate
appearance.
The
cells contain a parietal chromato-
phore
often with long
prolongations along
the
wall
of
the
cells
and
with
a
large
lateral
pyrenoid much
protruding into the
interior of the
cell
(Fig. 28)
;
in some speci-
,1
i
.
Fie
1
. 27.
Acrochsetium se-
mens
the chromatophore
is
large covering
ri
*
tum nov . spec.
Habit
nearly
the whole
wall
with
the
exception
of an erect ramified
fila-
of a small part near the ends
of the
cells; ^
3
34
in others
it
is reduced
to an
often
narrow belt
lying a
little above the middle
of the
cell.
The
sporangia
are
monosporous,
oblong-
ovate,
9
11
13
fj.
long,
69,
mostly
7
8//
broad.
They
are
as a
rule
sessile and
usually
secundly
seriated
in
long
rows
placed
on
the
inner
(upper)
side
of
the
branches
from
the
base
upwards
(Fig.
25
a);
but more
scattered
sporangia also occur (Fig. 27)
just
as pedicellate
sporangia are by no means
rare.
The
present
plant
has
a
great
likeness to
Chantransia Hypnese but
this
differs
in
having
Fig.
28.
Acrochse-
endophytic
basal
filaments.
Further
it
is
also
sp^'pirtTffiil-
related to Acrochsetium flexuosum Vickers.
But
merits
with
spor-
in
this
plant
the
monospores
are
secund upon
ang
450
1)
short ramuli, while
in the present the ramuli are
wanting,
the
monospores
being
placed
in
long
series upon
the
branches.
This species has been found mostly
in more
sheltered
localities.
It seems
to be common.
St. Croix:
Coakley
Bay,
Christians-
sted,
Lt.
Princess, Sandy Point;
St. Tho-
mas:
The Harbour.
9.
Acrochsetium flexuosum Vickers.
VICKERS,
A.,
Liste
des
Algues
de
la
Barbade.
(Ann. sciences
nat. IX
S6r., Bot.
1905, vol
1,
p. 60).
A
quite
certain
determination
derived from the somewhat imperfect
diagnosis of MUe VICKERS seems impos-
sible, and had the plant
I now suppose
to
be
this
species
not
grown
upon
Chastomorpha antennina
it had perhaps
not occurred
to me
to
refer
it
to this
species.
The plant found forms dense tufts
about
700 //
high;
it has a large base
Fig. 29. Acrochxtium flexuosum
composed
of creeping
filaments more
Vickers.
a,
part
of a filament
showing branchlets with spor-
or
less
fusing
together
in
the
inner
an gia.
b,
a young plant.
part,
(a, about 125:1.
&, about 160 :1).
35
Fig. 29 b
shows
a supposed young plant.
The
germinating
spore has given off a single cell, the earliest beginning of the creeping
basal
filaments, and from this
cell an
erect filament
arises.
In the
full grown
plant a great number
of
erect
filaments
grow up
from
the
inner
part
of
the
basal
part
;
those
in
the
middle
are
straight,
those
in
the
periphery
are bent
outwards.
In the lower part the filaments are about
9
10 p broad tapering
somewhat towards the summit where the diameter
of the cells
is
only about
6
7 //.
The
cells
are
about
2
3
times
as
long as
broad
in the basal part, reaching a length
of about 18
35^; in
the upper part the length
is about 30
35^.
The
cells
contain
a
parietal
chromatophore
(Fig.
30)
with
longer or shorter prolongations
along
the wall
of the
cell and a
large lateral pyrenoid protruding greatly into
the
interior
of the
cell.
The sporangia are situated upon small
secund
mostly
two-celled
branchlets
(Fig.
29 a)
; they are placed on the upper, inner
side
of
the
branches
upwards
from
the
axils.
They are ovate-oblong (Fig. 30); 14-
16^ long and
9
10
/j. broad.
This species
is evidently nearly related
to
Acrochsetium
Sagrasanum
Bornet 1
).
I
have compared my specimens with the large
Fig
30
Acrocheetium
plant
distributed
in
Phycotheca Bor.-Am.
flexuosum
Vickers.
a,
Nr.
39
under
the
name
of
Chantransia
^sporang^be'arin^*
1
mrgatnla and upon which BORNET has partly
branchlet.
b,
a
spor-
based
his
description
of
this
species.
But ^'^oT^oTl^^'
the
present
species
is much
smaller
and
differs among other things by having proportionally shorter
cells.
This species seems to be common upon Chsetomorpha antennina
of which the ends of the filaments often
are red coloured by the
epiphyte.
St. Croix:
Northside.
Geogr. Distrib.
:
Barbados.
10.
AcrochaBtium unipes nov.
spec.
Thallus usque ad 2mm altus, a basi ad apicem versus attenuatus.
Spora germinans, deorsum prolongationem subsphsericam endo-
1
) BORNET, E., Deux Chantransia corymbifera Thuret. Acrochsetium et Chan-
transia
(Bull.
Soc.
Bot.
Fr.,
t. 51, 1904,
p. XXI).
3*
36
phyticam
in cellulas hospitis, sursum filum erectum sporangiferum
emittens.
Filum
erectum
a
basi nudum
in
superiore
parte ramosum
ramis sparsis plus minus ramosis.
Cellule
cylindrical
in
inferiori
Fig. 32.
Acrochdetium unipes
nov.
spec.
Base
of
a
plant.
(About 450
: 1).
Fig. 31.
Acrochsetium unipes nov. spec.
A whole plant showing the basal cell and
the erect ramified filament with sporangia-
bearing branches.
(About 70
: 1).
Fig.
33.
Acrochsetium unipes
nov. spec. Bases of two plants;
a, seen from above,
b, in verti-
cal section.
(About 200
: 1).
parte
ca.
11
12
/j.
latse, 50^
Ionga3,
in
superiori
fere
bfj.
latse,
50
60
fj.
longas,
chromatophorum
parietale,
pyrenoide
laterali
instructum continentes.
Sporangia in
filis lateralia, uniseriata, sessilia, oblonga, 9
11
tj.
lata
et 2022^
longa.
37
This
species
was
found
in
a
depth
of
about
10
meters 1
)
growing upon Dictyota
linearis.
The
largest specimen found had a length
of up
to
2 mm.
The base
of
the plant
consists of
the
original
spore which
during
germination
penetrates
into
the
epidermal
cells
of
the
host
forming
a
process
(Figs. 32,
33)
;
this
is
thinnest
in
its
upper end where
it passes through
the
wall
of the
host broad-
ening more
out downwards
getting a somewhat
obovate-clavate
shape, by means
of which the plant becomes more strongly fixed
to the substratum.
The process reaches
in
all a length
of about
35 /* and reaches
often the lower wall
in the
cell
of the host plant.
The spore
itself
lies
freely above
the
wall
of
the
host
plant
;
it
is
nearly
spherical
with
proportionally
thick wall
; its diameter reaches a length
of about 2022^.
From
this
basal
body
a
single
erect
filament
grows
upwards
;
once
only did
I
find two
filaments
arising
from
it
(Fig. 33 b]
;
but
in
this
plant
the primary filament had been destroyed
and
then
another
one was
given
off
at the
side
of the
first
one.
The erect filament
is straight and
at
first not branched, higher up bran-
ches
are
given
off
to
all
sides
(Fig.
31)
;
these are
also very straight and
issued
from
the
principal
filament
FiS- 34 -
Acrochsetium unipes
nov. spec.
Part of the thallus
in
an
acute
angle
and
most
often
with sporangia. (About 425:1).
branched
in
a
similar way.
Against
their summit
all the filaments taper somewhat.
The
cells
in the principal
filament
and
the
lowermost
cells
in the branches
are
cylindric, somewhat
thick-walled,
their dia-
meter
reaching
a
length
of
about
9
11 p. and
their
length
up
to 50^.
In the summit on
the
other hand
the
cells
are
only
about 5
fji thick while their length
is about 50
60//.
The
cells contain a parietal chromatophore with a
pyrenoid
lying at the wall
(Fig. 34).
The
monosporangia
(Figs. 31 and
34)
occur upon the inner
l
) By a misprint
is the depth
in
vol.
I,
p. 210 said to be 40 meters.
38
side
of
the
lowermost
part
of
the
branches
;
they
are
in
the
specimens found always uniseriated and
sessile.
The sporangia are oblong clavate reaching a length of about
20
22
fj. and
a
breadth
of
9
11^.
The sporangia
found were
apparently not quite
ripe.
To judge from the description
of Acrochastium Hoytii Collins
1
)
this
plant
seemingly
comes
near
to my
plant.
Acrochastium
Hoytii seems to have a very similar base,
but
it has
1
3
erect
filaments which
only
reach
a diameter
of
about 6^;
further
it
appears
to
be more branched
and the sporangia are
pedicellate
and
much
smaller
than
those
in my
species.
I
wished
very
much to compare my plant with that distributed
in Phycotheca
Bor.-Am., No. 1540 and have
also examined the
material
distri-
buted but did
not
succeed
in finding
the plant
in the material
to which
I had
success.
Acrochastium unipes has only been found once
in a depth
of
about
6 fathoms.
St. Croix:
Frederikssted.
11.
Acrochsetium opetigenum nov. spec.
Thallus 1
2 mm altus.
Spora germinans globosa, processum
decumbentem
cuneiformem
in
cortice hospitis
(Dosyae
elegantis)
endophyticum
et filum erectum sporangiferum procreat.
Fila
erecta,
a basi ramosa,
cellulis
cylindricis ad 80^ longis,
ad basin ca. 8
11^
latis,
in media parte 13
14 //
latis ad apicem
versus paulo
attenuatis
ca.
6
1 p.
latis.
Chromatophorum parie-
tale pyrenoide
laterali instructum.
Ramificatio
uberrima,
rami
sparsi.
Monosporangia
sessilia
aut
pedicellata
ad
basin ramorum
2
3
praBsentia,
oblonga
vel
subcylindrica,
c.
11 /*
lata
c.
27 //
longa.
This
species
is the largest Acrochaetium found on the shores
of
the
islands
;
well grown
specimens
reach
a height
of
up
to
1
2 mm
or more and form a dense much branched
tuft.
The base
(Fig. 36)
consists
of the
original spore
from which
an
elongated
cuneate
prolongation
grows downwards and
pene-
trates
into
the
tissue
of
the
host
plant
(Dasya
elegans).
This
endophytic part reaches a length of about 20^.
In some
plants,
especially the older and more vigorous
(Fig.
36 b)
is
furthermore
developed
one
or
a
few
short
horizontal
1
) COLLINS,
F.
S., Two new
species
of Acrochaetium (Rhodora,
vol.
10,
1908,
p. 134).
39
filaments
from
the
lowermost
part
of
the
spore.
These
fila-
ments
consist
of
a
few
cells
only and
lie
along
the
surface
of
the host
in which they are
not
imbedded,
or
at the most
only
a
little
on
their
lower
side.
From
the
cells
in these
creeping
filaments
erect
ones
were
found
growing up
in a
few vigorous
specimens
(Fig. 36 b).
The
spore
itself
is
quite
globular,
about
17
fjt
in diameter;
it
lies upon the surface of the host plant.
The
plants
are mostly fixed
at
the
base of the pinnules of the host
and many plants are often found
surrounding
each
pinnule
(Fig.
36 a).
Most
probably
the
ger-
minating spore finds more shelter
here.
But plants occur also on
other
parts
of
the
host
and
even upon
the
pinnules
them-
selves. From each spore a single
(or
in more vigorous plants two
or more)
erect
filaments
grow
up.
They
consist
of
cylindric
cells
;
in
the
basal
part
their
diameter
is
about
8
9
11 ^,
higher up the diameter increases
and in vigorous plants it reaches
a
length
of
1314 p.
The
length of the
cells
is often 80 p.
and
more.
Towards
the
sum-
mit
the
filaments again
taper,
their
diameter
reaching
only
6
7^,
but
the
ends
are
not
hairlike
and
the
cells
contain
both
chromatophore
and pyre-
noid
(Fig. 35).
The chromatophore (Fig. 37)
is
parietal,
often with
long
prolongations
along the
wall
of
the
cell and
it contains a large
lateral pyrenoid protruding markedly
intp the
interior
of the
cell.
The
ramification
begins
from near
the base
but
is
further
developed higher up.
It
is
multilateral and the branches ramify
copiously in
the, same manner.
The sporangia
(Fig. 35,
37)
are
oblong-oval
or more
elong-
ated,
subcylindric
or
subclavate.
They
are
mostly
sessile
but
Fig. 35.
Acrochaetium opetigenum
nov. spec.
Small part
of an
erect
ramified filament.
(About 90
: 1).
40
Fig.
36.
Acrochsetium opetigenum
nov. spec.
a, Transverse section
of Dasya elegans
with
basal
parts of three plants two of which fixed to the base
of a pinnule and showing
the cuneate endophytic
process penetrating into the tissue of the host and
one fixed
to the pinnule
itself,
b, basal part of an
older vigorous plant showing the endophytic cuneate
process and further two short epiphytic branchlets
;
from that to
the
left an
erect filament
is issued.
(About 200: 1).
pedicellate examples
also occur. The spor-
angia
are
placed
upon the lowermost
cells of the branches
mostly only two
or
three upon each fila-
ment
; but they also
occur upon the main
filaments.
COLLINS
has
de-
scribed an Acrochse-
tium (A. Dasyae) also
found
upon
Dasya
elegans which seems
closely related to the
present
species.
It
has
for instance the same globular persistent basal spore but this
emits, as described by COLLINS, "a short, descending process, some-
times branched,
of
a few
small rounded
cells,
attached
to the host".
I
have
examined
the
specimens,
distributed in Phycotheca Bor.-Am.,
No. 1342 and have seen these short,
2
3 celled
branches. As far as
I can observe these branches
are not endophytic and they are upon the whole
quite
different to the descending process found
in my plant.
Besides this difference my species
has a very different appearance,
is much larger
in
all parts of the thallus, much more branched
and the ramification
is not secund.
Found upon Dasya elegans
in
a
depth
of
about 20 meters.
St. Jan:
Off Cruz Bay.
12.
Acrochsetium
robusttiin nov. spec.
Thallus
ceespitosus, usque ad
1 mm longus,
e
filis
erectis
et
filis horizontalibus
epiphyticis
compositus.
Spora germinans
in texturam hospitis pau-
lum penetrans
;
a superiori parte, non immersa,
fila brevia repentia, plus minus
lateraliter con-
Fig.
37.
Acrochse-
tium opetigenum
nov. spec.
Sporan-
gia-bearing filaments
with chromato-
phores and pyreno-
ids. (About 400:1).
41
Fig. 38.
Acrochsetium robustum
nov.
spec.
Base of a plant.
(About 450
: 1).
fluentia,
egrediuntur,
et
sic discum
basalem
formant,
ex
cellulis brevi-
bus, diametro fere sequilongis, pariete
crasso compositum.
Fila erecta a basi
ramosa,
apicem
versus
sensim pau-
lum attenuata, in parte basali 9
10 p
lata, superne
ca.
5 p.
Cellula? cylin-
dricse
9
10 //
lata?,
inferiores
15
20
fj. longse, superiores ca. 40 // longse,
chromatophorum parietale, pyrenoide
laterali instructum continentes.
Kami sparsi, nonnunquam secun-
dati, ramulis sparsis,
uni-, bi- aut
tri-
cellularibus, monosporangia gerentibus
instruct!.
Sporangia ovata,
ca.
11
/j.
lata
et
12
14 // longa.
This
species was
found
together
with
several
other
species
upon
old
leaves of Sargassum vulgare.
The base
(Fig.
38)
of
the
plant
consists
of
a
pluricellular
disc composed
of
thick-
walled
cells.
From
this an unicellu-
lar, thickwalled
process grows down-
wards
fixing the plant strongly to the
host
plant
;
how
far
these
processes
also
should
serve
as
haustoria
like
those
described by
ROSENVINGE
for
Chantransia cytophaga, I have not been
able to
decide.
The
processes
reach
a
length
of
about
20 n
;
the
basal
disc
is about
8
10 //
thick.
Not
having
succeeded
in finding
quite young
plants
I have not
been
able
to
follow
the
development
of
the
basal
disc,
but
most
seemingly
the
germinating
spore
produces
the
process
during
germination
(com-
pare
Fig.
38)
and
this
grows
down-
Fig. 39.
Acrochsetium robustum ward s
jn
the
tissue
of
the
host
nov. spec.
Habit of a plant.
(About 140:1).
plant; afterwards from
its upper end
42
short horizontal filaments grow
out which fuse together forming
the
disc.
From
the
cells
in
the
disc gradually
several
erect
ramified
filaments grow upwards forming a dense tuft
(Fig. 39).
The principal filaments
consist
in
their
lower
part
of
short
cells about l 1
/^
2 times as long as broad, their diameter reaching
a length
of about
9
10 ju; upwards the filaments become gradu-
ally
thinner and
the
cells
at
the
same
time
longer.
Near the
summit they are only about 5^
thick and
often
upto 40 // long
or more.
Sometimes the cells in the lower part
of the principal
filaments
are
a
little
broader
in the middle tapering towards both ends.
The
chromatophore
(Fig.
40)
is
parietal
often
with
some
longer
prolongations
along
the wall
of the
cell and
contains a large pyre-
noid projecting somewhat
into the
interior
of
the
cell.
The
ramification
of
the
filaments begins
near their base, but on the whole the filaments
are
not much
branched.
Branches
are given
off
to
all
sides but often with long interwalls.
Two
kind
of
branches
are
present,
long
fila-
ments
like the principal ones and short branch-
lets upon which the sporangia
are borne.
The
branchlets
are
as
a
rule
one-
or
two-celled
;
in
the
first
case
it bears a
single
Fig.
40.
Acrochse-
terminal
sporangium,
in
the
latter
the
lower
tium robustwn nov.
n
i
i
T
n
i
spec. Part of a
fila-
cell also bears a mostly pedicellate, more rarely
ment with
sporan-
sessile, sporangium. The last mentioned branch-
gia-bearing branch-
.
,
,
lets. (About 700:1).
lets occur mostly in the lower part of the tufts,
while
the
first
mentioned
as
a
rule
are
only
present
in the upper part.
Only rarely are the sporangia seated
directly upon
the main
filaments.
Branchlets
with more
than
two
cells
are
rare.
The sporangia
(Fig.
40)
are monosporous,
oval-ovate, about
11
fj. broad and about
14
16 /* long;
they
are
provided with a
very thick wall, often up
to
2//
thick.
This
species seems
at first sight to come near to Acrochaetium
Hypness
;
but
it
differs
in a
different arrangement
of the
spores,
these
being
sessile
and
seriated
in
Acr. Hypneae;
further
Acr.
Hypnese
has
endophytic
filaments
which
I
have
not
found
in
43
the present
species, and the sporangia are rounder and have not
the thick wall
of Acr.
robustum.
Found upon Sargassum vulgore
in sheltered
place.
St. Thomas:
The Harbour.
13.
Acrochsetium bisporum Bergs.
Chantransia
bispora
Borgs., Some new
or
little known West
Indian
Florideae,
II ("Botanisk
Tidsskrift",
vol.
30,
1910,
p. 178).
Fig. 41.
Acrochaetium bisporum Bergs.
A,
part of
a plant with sporangia
with two
spores.
B,
part of
a plant with
monosporangia.
C,
sporangia
with two spores.
D,
cells with chromatophore and pvrenoid.
E,
a young
plant.
F, G, H, I, basal parts of plants.
(A, B, about 120 :1, F, G, I, about
250:1, C,D,E,H, about 350:1).
In the former description
of
this plant,
I have pointed out
that
it
is perhaps nothing more
than
a
variety
of Acrochaetium
Hypneae.
I
had
hoped
when
looking
through my
collections
to
refmd
it
again
and
by
a
renewed
examination
be
able
to
settle
this question.
44
But unfortunately
I have not been
successful and
therefore
I am
forced
to
adhere
to my
former
position.
As there men-
tioned
this
species was found upon Acanthophora spicifera (Vahl)
Bergs.
From the basal
cell which to begin with
is roundish and
thickwalled
(Fig. 41 E) short creeping filaments grow out
;
some
of these
are epiphytic creeping upon the
surface
of the Acantho-
phora,
others penetrate into the tissue
of the host-plant (Figs. 41
F, G, H, I)
but
it
sometimes happens
that young
plants occur
which
are
not
at
all
parasitic.
From
the
basal
layer
several
erect
filaments
gradually
arise.
The
cells
are
usually
a
little
constricted
at
the
cross-walls
;
they
contain
a
well-developed
parietal chromatophore with a large
lateral pyrenoid.
The
cells
are about 8^
broad and about
20 // long and mostly
2 l/2 times
as long as broad with some variations.
The filaments are usually
only
slightly branched
in the lower part, more so higher up; the
side-branches grow out
at an acute angle from the mother-branch
and
in well-developed plants the branches are again multilaterally
ramified.
Most
of the specimens had monosporangia
; these
are ovate-
oblong,
Qfj.
broad and 10 n
long,
as
a
rule
sessile,
more rarely
pedicellate,
serially arranged upon the upper side of the branches.
Sporangia divided
into two
spores were only found in few plants
;
these
are larger than
the monosporangia,
oval, about
9 p. broad
and
14
fj.
long
;
they
are
mostly
sessile,
sometimes
pedicellate
or
placed upon
short
branchlets.
In my
former
description
I
remarked
that
a
single
sporangium
was
found
in
which
the
upper
half was
again divided by a
vertical
wall.
How
far this
suggests that the
plant
in
reality has tetraspores, the specimens
found representing only a young state
of development, can only
be
settled by means
of more material.
Acrochsetium bisporum has been
found
only once,
in the Harbour
of
St. Thomas.
Geogr. Distrib., Danish West
Indies.
14.
Acrochsetium
occidentale nov.
spec.
*
Thallus usque ad
1
2 mm
altus,
e
filis erectis ramosis spor-
angiferis
et
filis endophyticis
constructus.
Spora in filamentis assimilatoricis hospitis germinans, magna,
ovata
globularia,
e
parte
basali
fila
circum filamenta hospitis
repentia,
e
parte
superiori filum erectum singulum
gignit.
Filum
erectum
inferne nudum media parte ramosum,
ramis
sparsis ad apicem versus
attenuatis instructum.
4,')
Cellulee
cylindricee
in
inferior!
parte
filorum
ca.
11 ft
latae
40 ft longse,
in
superior!
7
8// latse 40^ long*, chromatophorum
parietale, pyrenoide
lateral!, instructum continentes.
Sporangia sessilia,
raro pedicellata in parte
basali ramorum uniseriata, monospora aut raro
bispora, ovalia, ca. 18
20/j. longa et 9
12/2 lata.
The basal part
of this
species
is immersed
in the mucilage and
chalk incrustation
of the
host plant (Liagora elongata).
On germination the spore does not divide
and remains throughout undivided
;
its diameter
is about
16/!/. After the germination it produces
endophytic filaments from
its lower
side
; these
creep downwards fixing themselves
to the
assi-
milating filaments of the host plant (Fig. 42
c).
From the upper end an
erect filament
(or
sometimes two)
is given off
(Fig. 42 a)
; this
is
at
first undivided
but
after having grown
so
that
it
is
quite
free
of
the Liagora
tissue
it
becomes
branched.
The ramification
is some-
what
slight.
The branches are given
off at an
acute
angle
and
the
branches themselves
are
ramified
in
the same way
giving
the plant a
cluster-like appearance.
Towards
the summit
the
branches
taper
into
hair-like filaments the
cells
of
which
are
long and nearly colourless
and
soon
die away
at the end
(Fig. 42 a).
The cells in the filaments are about 10
11 ft
thick and about 27
40
it long;
near the base
the
filaments
are
a
little thinner,
about
8 ft
;
in the
hairlike
ends
the
cells
taper
to about
7
80.
The
chromatophore
(Fig.
43)
is
parietal,
often with elongations towards the wall of the
cell and
it encloses a
lateral pyrenoid.
The
sporangia
(Figs.
42 a, b,
Fig. 43)
are
sessile,
oval-ovate.
They
are
about
9
12
ft
broad
and
18
20
p.
long.
Monosporangia
mostly
occur,
but
in
a
few
specimens
some
were divided by a transverse wall into two spores
(Fig.
43).
It
is
perhaps
not
impossible
that
Acrochaetium
Barbadense
Fig. 42.
Acrochae-
tium
occidentale
nov. spec,
a, erect
filament with spor-
angia,
b, part of a
filament with spor-
angia,
the
upper-
most divided
into
two
spores,
the
lowermost emp-
tied,
e, base of a
plant
fixed
to
the
assimilating
fila-
ments
of Liagora.
(a,
about
1'25
: 1;
b, 250:1; c, 200:1).
46
Fig. 43.
Acro-
chsetium
occi-
dentale
nov.
spec.
Branch
with
sporan-
gia, the upper-
most
divided
into two
spo-
res.
(About
400: 1).
(Vickers)
is the same as this species. But the descrip-
tion of M lle VICKERS
is so defective that any identifica-
tion- by help of
it
is impossible and
as: "Les echan-
tillons,
mal
conserves,
ne
se
pretent
pas
bien
a
1'etude", any help from the
original material seems
also
excluded.
The
bases
of
the
two
plants
in
question
are
apparently
alike
and
they
are
both
living
upon
Liagora.
BORNET and Mlle VICKERS
refer the plant
to Chantransia which
suggests
that the plant
from
Barbados
had
sexual
organs
;
these
I
have
never
found
in my plant.
As to
the arrangement
of the
monospores
of Acr. Barbadense,
their form and
size
nothing
is
said
just
as
no
description
is
given
of
the sexual organs.
St. Croix:
Long Point.
15.
Acrochaetium comptum nov.
spec.
Thallus usque ad 1 mm altus
et ultra,
e
filis
erectis ramosis sporangiferis
et
filis
endophyticis compositus.
Spora in filamentis assimilatoricis hos-
pitis germinans, magna,
oblonga, in cellu-
las
duas
divisa
est
;
e
cellula
inferiori
fila decumbentia
circa
filamenta
hospitis
repentia, e cellula superiori filum singulum
erectum
gignitur.
Filum erectum inferne nudum, superne
ramosum ramis vicissim plus minus ramo-
sis ramos seriates gerentibus instructum.
Cellulse
cylindrical
8
ll//
Iata3,
ca.
35 fjL longa?, chromatophoro parietale pyre-
noide
laterali instructs.
Sporangia monospora, plerumque ses-
silia, nonnumquam
in
ramulis
unicellu-
laribus
posita,
singula vel
bina,
in
parte
basali ramorum uniseriata, ovata, 11
14^
lata
et
18 ;i
longa.
This
species
is characterized by
the
J
.
.
fact that the germinating spore
is divided
part
of
a
plant showing
by a transverse wall
into two
cells
from
the original spore divided
into
two
cells.
(About
the
upper
ol
which
an
erect
tilament
350
: i).
Fig. 44.
Acrochsetiuin
compium nov. spec.
Basal
47
"*
grows upwards, while from the lower endo-
phytic
filaments
growing downwards
are
produced
(Figs. 44, 45 c and
d).
The
last
mentioned filaments grow downwards round
the
assimilating
filaments
of
the Liagora
upon
which
the
spore
has
germinated.
They do
not
penetrate
into
the
cells
of
the host plant but only into the mucilage
and chalk incrustation
found between the
filaments.
The
main
filament
arising
from
the
germinating spore remains
in most
of the
specimens
undivided
in
the
basal
part
(Fig.
45
a),
but
specimens were
found
in
which a single or few branches were given
off
from
near
the
base.
In some
of
the
more adult specimens
erect filaments were
found
growing up
from
cells
in
the des-
cending filaments
(Fig. 44).
On one occa-
sion
a
descending
filament
was
found
growing
out
from
a
cell
near
the
base
,
of
the
erect filament
(Fig. 44).
The
cells
a, habit of erect, ramified
in these are about 8-11,, broad and
their
length about
35/,<.
When the
erect filaments have grown
long enough to become free of the Liagora
they begin to branch more
freely.
The
branches
issue
from
the
upper
end
of
each
cell
mostly
in
an
uniseriate
manner;
these
branches bear again
branches
arranged
secundly.
Towards
their
apex
the
branches
are
undivided
tapering somewhat becoming about
8
[j> thick,
at
the
same
time
the
chromatophores
are
not
so
well developed.
The
chromatophore
is
parietal
(Figs. 44,
46)
with a large pyrenoid.
The
sporangia
are
broad
oval
and
mostly
pedicellate
(Figs. 45
a, b,
Fig.
46),
placed
upon
snort
secund
branchlets being
seriately arranged
tium comptum
.
-j
*
xi
i_
rfi
nov. spec.
Part
upon the upper, inner
side
of the branches.
[ he
of
a
filament
branchlets
are
as
a
rule
one-celled
and
bear
with
sporangia.
.
.
c
-i
(About
400
i)
mostly a
single sometimes two sporangia.
Sessile
sporangia,
c and d, bases
O
:
(
1; c
'i50:
l).'
48
sporangia
also occur often rather numerous especially in the upper
part
of the
plant.
The diameter
of the sporangia
is about
11
14//, the length about
18/*.
This
species has been found upon Liagora pinnata.
St. Croix:
White Bay.
16.
Acrochsetium Avrainvillese nov.
spec.
Thallus
ca^spitosus
usque
ad
1 mm
altus.
Pars
basalis ex
interiori parte plectenchymatis hospitis emergens, ex
filis brevibus
in
filis
hospitis
externe
repentibus
composita.
Tota
planta
a
basi
ad
apicem
sensim attenuata.
Fila
erecta,
a
basi
simplicia,
in
superiori
parte
ramosa,
ramis
multi-
lateralibus,
rectis,
plus minus ramosis
instructa.
Cellulse cylindrica3,
in parte basali
ca.
9 n
lata?
33 /j.
longae,
ad
apicem
b
versus
ca.
4//
latse 50 //
longse,
chro-
matophorum parietale, pyrenoide late-
rali instructum continentes.
Sporangia
sessilia
aut
interdum
pedicellata,
sparsa aut pauca
seriata,
oblonga,
11 //
lata,
22 u
longa.
This
plant
was
found
upon
an
old specimen of Avrainvillea nigricans.
The
basal
part
of
it was
fixed
to a
filament of the host plant lying rather
deep
in
the
cortical
plectenchyma
(Fig. 47 a)
; on account
of
its very loose texture the Acrochsetium
has no
difficulty in growing out through
it, and
as
I have only
met with two specimens
of
it
in
all
I
dare
not
deny
the
pos-
sibility
that
the
Acrochsetium
might
be
found
quite
epiphytic
upon the external filaments
of the host.
The basal part
consists of short, creeping filaments attached
to the
surface
of
the
filaments
of
the host
plant
;
they consist
of proportionally short and thick-walled
cells.
From the
cells in the middle of the basal filaments the erect
ones
are given
off (one or more).
At
their base
the
erect filaments are
unbranched
(Fig. 48)
;
Fig. 47. Acrochsetium Avrain-
villese nov. spec,
a, filaments
of Avrainvillea nigricans with
the
basal part
of
the Acro-
chsetium.
b, base of the same
plant more magnified.
(a, about 40: 1;
b, 700: 1).
49
higher up when they have become
free of the host plant do they
begin to branch. They are multilaterally ramified and the branches
are
straight and given
off from the axis
at an acute
angle.
The principal filaments are thickest
near
their
middle
or
a
little
above
where the ramification begins
; here the
diameter of the
cells reaches a length
of about
9
fji.
At their base the cells
are only about
5,5 p
thick.
Towards
the summit the branches taper again,
the
cells
here
becoming
thinner and
at
the
same
time
longer
and
with
less contents.
The
cells
are
cylindri-
cal,
not constricted
at the transverse
walls,
in
the
basal
part
about 33^
long,
while
near
the
summit on
the
other
hand
their
length
can
reach
50//
or more.
The
chromatophore
(Fig.
49)
is
parietal,
often
not
much
developed
and contains a large lateral
pyrenoid
projecting greatly into the
interior of
the
cell.
Fig.
48.
Acrochaetium Avrain-
Fig.
49.
Acrochsetium
AvrainviUese
nqv.
villese nov. spec.
Habit of erect
spec,
a, part of a filament with sporangia,
ramified filament with sporan-
b,
cell with chromatophore and pyrenoid.
gia.
(About
70
:
1).
(About 600
: 1).
The monosporangia
(Figs. 48,
49)
are
sessile
or more rarely
pedicellate,
usually occurring on
the
inner
side
of
the branches
near
their base,
seriate or
a few together
; but sometimes more
irregularly.
4
50
The sporangia are oblong, about
22 ^ long and
11
/j. broad.
Found once only
in deep water (about 20 meters).
St. Jan:
Off Cruz Bay.
17. Acrochsetium hormorhizum
nov.
spec.
Thallus
ca?spitosus
usque
ad
1 mm
altus
et
ultra,
e
filis
endophyticis
brevibus
horizontalibus ramosis et filis
erectis,
a
basi ramosis, spor-
angiferis constructus.
Fila
endophytica
in
ex-
^^^^^^^_
I
teriorem
partem
membranes
Fig. 50.
Acrochsetium hormorhizum nov.
cellularum hospitis (Champix
spec.
Base of a plant.
(About 250
: 1).
parvulx) penetrantia, ex cellu-
lis
brevibus
pariete
crassiori
composita,
discum
basalem
minorem
supra
cellulas
maximas
hospitis
formantia.
E
disco
basali
fila
erecta
creantur,
ramis numerosis plus
minus ramosis sparsis
in superiori parte filo-
rum
uniseriatis.
Cellules in
inferi-
ori parte filorum dia-
metro
fere
4
5 - plo
longiores,
9
11
//
latse
,
in
superiori
parte 8
9// latse dia-
metro
fere
7-plo lon-
giores.
Chromatopho-
rum
parietale,
pyre-
noide
laterali
muni-
Fig. 51.
Acrochsetium hormorhizum
nov. spec.
Sporangia
sessi-
a, habit
of a
plant,
b, filaments with sporangia.
lia ant rariiis nprlirpl
c > base
of
a
Plant
seen from
above -
( a >
about
' P e
70:1;
b, 150
: 1
;
c, 250:
1).
lata, sparsa aut pluria
seriata, oblonga,
fere 20
22 n longa
et 10
11
/j.
lata.
This
species
was
found
on Champia parvula upon
which
it
forms small cushions about
1 mm high.
51
spec. Part of a
filament with
The germinating spore grows downwards
through
the thick
peripheral
wall
of
the
host
plant
until
it
arrives
at the more
compact
innerwall
of
the
cells.
Here
it
ramifies
sending
out
some
few
short
horizontal
branches
(Fig. 50).
These
consist
of thick-walled
cells
nearly
as long as broad or a little longer and much swollen
in their middle
part,
the endophytic filaments thus
assuming a moniliform appearance
(Fig. 51
c).
The
length of the cells is about 12
14 y. and the breadth
about
11 p.
From this endophytic basal part the
erect
free
filaments
arise
(Figs. 50,
51 a,
c).
These are more
or
less
ramified through their whole
length,
in the
lowermost
part
on
all
sides,
but
higher up
often
uniserially
;
they
taper
only
slightly towards
their
summits.
The filaments
consist
of
cylindrical
cells
chaetium
'
hor-
which
at
the
basal
part
are
about 911 u broad
and
about 30
50 p
long,
in the upper end
8
9 ^
broad
and
about 60 //
long.
The
branches ramify
f /-P
rf^f^'-ii
repeatedly. All the branches are mostly rather straight.
The
cells
contain
a
plate-shaped
chromatophore
(Fig. 52)
with a
well
developed
pyrenoid
protruding somewhat
into
the
interior
of the
cell.
The sporangia (Figs. 516,
52)
are
mostly
sessile but
some are pedicellate. They
occur
as
a
rule upon the
lowermost
cells of the
fila-
ments
seriate
upon
their
upper
side,
but now and
then
also more
scattered.
The
sporangia
are
ob-
long-elliptic of shape, about
2022 ft long and 1011 //
broad.
Found
once
only
in
a
sheltered
locality.
St.
Croix:
Christiansteds
Lagoon.
ft
Fig.
53.
Acrochsetium Hypneae B0rgs.
Base
of a plant.
(About 300
:
1).
18.
Aerochsetiuni Hypneae
B0rgs.
Chcmtransia Hypneae B0rgs., Some new
or
little known West Indian
Floridese,
I
(Bot.
Tidsskr.,
30.
Bd., Kobenhavn
1909).
52
As
pointed
out
in my former description
this
species
is an
endophyte
growing
upon
Hypnea.
I
have
examined
it
again
and give now
a new figure
of the basal part (Fig. 53).
As the
figure
shows
the
base
consists
of
short
horizontal
filaments
creeping
in
the
thick wall
of the host.
The
cells
in these
fila-
ments are
short, only a
little longer than broad, and from these
cells the
erect sporangiferous filaments grow upwards often seve-
ral
together
forming in this
way
small
tufts
upon
the
host.
The
erect
filaments
are
not
very
richly
branched
(Fig. 54)
; the branches grow
out
at
an
acute angle from
the
mother
branch.
The
ramification
is
multilateral
with
some
tendency
in
the
upper part to be
secund.
The
cells
are cylindrical,
usually 2
4 times as long as
broad.
They contain a well
developed
parietal
chroma-
tophore
(Fig. 54 b)
covering
nearly the whole wall
of the
cell and have a large
lateral
pyrenoid.
The sporangia are
seriate
on the upper side
of
the branches,
sessile
or very
rarely pedicellate.
If
the basal part
is
left
out
of
consideration
it can-
not be denied that the above,
described Acrochsetium
seria-
tum shows great
likeness
to
this
species.
But while the present
plant
has an endophytic base the other
is
epiphytic.
This species has been found in a small lagoon with shallow water.
St. Thomas:
The Harbour.
Geogr. Distrib.
:
Danish West
Indies.
19.
Acrocliaetium repens nov.
spec.
Thallus
e
filis endophyticis
et
filis sporangiferis
erectis com-
positus.
Fig. 54.
Acrochsetium Hypnese B0rgs.
A, plant with monosporangia.
B,
cells
with chromatophore and pyrenoid.
C,
D, E,
hasal
parts.
(A,
about
125
: 1
;
B,
C, about 250
: 1
;
D, E 200
: 1).
53
Fila
endophytica
irregulariter
ramosa
sub
cellulis
epider-
malibus
hospitis
horizontaliter
repentia,
e
cellulis
medio
plus
minus
irregulariter
inflatis constructa.
Fila
erecta,
ad
500 //
alta,
ramosa,
apicem versus
sensim
attenuata,
e
cellulis
ad
basin 78 //
latis, superne
2
3
latis,
inferioribus
c. 24^
longis,
superioribus
c. 50
,
longis
et
subhya-
linis constructa.
Chromatophorum
parie-
tale
pyrenoide
laterali
in-
structum.
Sporangia
oblonga, 14^
longa
et 8p lata in ramulis
unicellaribus
solitaria
vel
bina, raro
sessilia adsunt.
Fig. 55.
Acrochsetium
repens
nov.
spec.
Two erect ramified filaments with spor-
angia and the basal creeping part.
(About 300:
1).
Fig.
56.
Acrochsetium, repens nov.
spec, a and b, erect filaments with
sporangia,
c,
endophytic,
basal
filaments seen from above.
(About 260
: 1).
This
species was
found
upon
a
Gracilaria-Mke
plant.
The
endophytic
filaments
creep
below
the
surface
cells
of
the host
(Fig. 55),
forming
a
nearly
reticular expansion
(Fig. 56 c).
The
basal filaments are irregularly ramified, consisting of barrel-shaped
or more irregularly formed cells more or less swollen in the middle
and much tapering towards both ends.
54
Now and
then from these
cells erect filaments
arise penetra-
ting through the epidermal layer of the host plant (Fig. 55).
The
erect
filaments
reach
a
length
of up to 500 /*.
Below they are
about
7
8u
thick and the length
of the
cells about 24^.
Up-
wards they taper
gradually and
end with long nearly
colourless
hair-like
threads;
the
cells
in
these threads may reach a length
of up to 50 fj. or more and are
2
3^ thick.
The erect
filaments
are
multilaterally or very seldom oppo-
sitely ramified and the branches taper
in the same way into
hair-
like ends.
The chromatophore (Fig. 55)
is
parietal
with
lobed
margin
and
with
a
lateral pyrenoid
often
projecting
considerably
into
the
interior of the
cell.
The
sporangia
(Figs. 55, 56
,
b)
are
placed
at the base
of
the branches
or upon branchlets.
They are nearly always pedi-
cellate,
but now and then
the uppermost
sporangium
is
sessile.
The sporangia are oblong, about 14 // long and
8// broad.
Found only once
in a sheltered
locality
in shallow water.
St. Thomas:
The Harbour.
20.
Acrochsetium phacelorkizum nov.
spec.
Thallus
caespitosus ad
1 mm
altus
et
ultra,
e
filis endophy-
ticis et
filis
erectis ramosis sporangiferis compositus.
Fila endophytica
inter
assimilatores
hospitis immersa,
saepe
aggregata,
in superiori
parte ramosa,
e
cellulis
ca. 40
fj. longis
et
2225, raro 21 ju.
latis
orta.
Fila
erecta, apicem versus sensim attenuata,
a
basi
ramosa.
Kami
in
superiori
parte
filorum
numerosi,
sparsi
aut saepe uni-
seriati.
Chromatophorum
parietale pyrenoide
laterali instructum.
Monosporangia
sessilia,
sparsa aut
seriata,
oblonga, 12
14 /*
lata, 22
24
(j. longa.
This plant was found upon Codium elongatum and isthmocladum
among the utricles of which the basal part
is immersed while the
upper free-growing filaments form tufts about
3
4mm high.
Some small differences were present
in my specimens;
I
shall
first
describe those found in Codium elongatum.
The
basal part
(Fig. 57) consists of proportionally very thick
filaments
creeping downwards
along the wall of the
utricles and
between
them;
in the
uppermost
end
the endophytic filaments
are
ramified
sending downwards
from the lower end of the
cells
00
new endophytic
filaments
while upwards
from
their upper ends
the
assimilating and
spore-bearing
filaments
arise.
In
this way
the endophytic
filaments
form together proportionally dense
clu-
sters as most of the filaments run downwards nearly side by side
;
but now
and
then
also
endophytic
filaments
are found
which
bend
outwards
to
the
side,
thus
giving
rise
to new tufts
in a
similar way
to
that
described by
ROSENVINGE
for Acrochsetium
Nemalionis.
But in Acrochsetium phacelorhizum
it seems to be not
so common.
The endophytic filaments reach a thickness of up to
27
fj.
and
the length
of the
cells
is about
36/^.
Most often they are thickest at the
lowermost
end
tapering
gradually
up-
wards.
The wall
of the filaments is often
somewhat sinuous.
From the upper end of
this rhizome-
like base the
erect filaments
arise as men-
tioned above forming a more or less dense
cluster;
in
a
vigorous
plant
about
4
6
filaments
are
present;
the remnants
also
of
several
broken
off
or dead
filaments
are
often to be found.
The
erect
filaments
(Fig.
58)
have
spreading
branches,
in
the
upper
part
with some tendency
to
unilaterality.
The
filaments
are
thickest
in
the
lowermost
part, about 11
12 /*, tapering very grad-
ually
towards
their
summit,
being
here
about
6//
thick;
these
thin
ends
of the
filaments
die
gradually
away.
In
spec-
imens
still
in
vigorous
growth
the
fila-
ments
have blunt ends and do not taper
so much.
In the lowermost part the cells
are about 40^ long, being mostly a little
longer
upwards,
about 54^.
The
cells
are
cylindrical
and not
constricted
at
the
transverse
walls.
They
contain
a
parietal
chromatophore
(Fig. 59)
with
a
large
pyrenoid
protruding
con-
siderably into the
interior
of the
cell.
In
the
specimens
found
the
sporangia were
not present
in
great
number.
They
occur
often
a
few together
seriately near
the base
of the branches but, often also quite scattered
(Fig.
58).
All
the
sporangia
found
were
sessile
and
monosporous, oblong,
Fig.
57.
Acrochsetium
phacelorhizum
nov. spec.
Two
basal
parts.
(About KID: 1).
56
about
12
14
fj. broad and 2225^
long.
At the summit
of the
sporangia a small thickening
is
often present
(Fig. 59).
The specimens found
in Codium isthmocladum
agreed
in
all
essentials
with
those
described
above,
but some
small
differences
were
noted.
Thus the basal endophy-
tic
part
of
the
plant
was often looser, not so
tufted together as shown
in
the
fig. 57
and
the
endophytic
filaments
were
a
little
thicker,
about
33//.
Also
the
erect
filaments
were
somewhat
thicker
,
at
their base about 14
15//
thick, at the apex about
6
IfJL.
Several
species
of
Acrochgstium
occurring
upon Codium have been
previously described. The
brothers
CEOUAN
have
found
the
Acrochsetium
(Callithamnion)
Codii 1
)
upon Codium elongatum.
Of
this
species
Dr. Ro-
SENVINGE has ben
able-
to examine
original ma-
terial
and
has
most
kindly shown me a fine
preparation from which
it
is clear that my plant
Fig. 58. Acrochsetium phacelorhizum nov. spec.
has nothing
to do with
Uppermost
part
of
the
basal
part with
an
^^
species.
Dr. ROSEN-
erect
ramified sporangiferous filament.
.,,
,
(About 50
:
1).
VINGE
will
later
give a
description of this plant.
*) CROUAN,
P.
L.
et
H. M.,
Florule du
Finistere,
1867,
p.
135
(nomen
nudum).
Cfr. BORNET, Deux Chantransia
corymbifera
Thuret
(Bull.
Soc.
bot. France, Tome
51,
1904,
p. XX).
57
In "Forschungsreise
S. M.
S.
Gazelle", IV part,
Bot.,
p. 31
ASKENASY has described the Acroch&tium (Chantransid) Naumanni
in which the sporangia seem to have a similar thickening
of the
membrane
at
their summit
as
in the present
species,
but
in
its
whole appearance and
in
its way
of
growing,
quite
or
nearly
quite immersed
in
the
host
plant,
it
is very
different
from my
plant.
The
Acrochsetium
(Chantransid)
interpositum
Heydrich
1
)
must
be
identical with ASKENASY'S
species
and
is
in any
case
highly distinct from my plant.
Finally as to Callithamnion poly-
rhizum Harv. 2
), this plant also seems to be very
different.
Mr. A.
D. COTTON
has most kindly
examined
for me
a
little fragment
of
the
ori-
ginal plant
of HARVEY.
From this
it is evident
that HARVEY'S plant
is much larger and
quite
different
from
the mine
having much
likeness
to Rhodochorton.
Of
species not found
in Codium our plant
has some
likeness
also
with
the
Acrochsetium
(Callithamnion} Nemalionis De Notaris of which
a
very
detailed
description
is
given
by
Ro-
SENVINGE
(1.
c. p.
126).
But Acroch. Nemalionis
has,
as
described by ROSENVINGE,
"long rami-
b,
cell
of the main
filament with chro-
matophore and
pyrenoid.
(About 250
: 1).
fied filaments growing widely in the interior of
nov.spec. a, filament
the host and here and there sending out through
the
surface
of
the
host
free
filaments
giving
rise to new tufts."
This
I have not found
in
my plant.
And
further in Acrochsetium Nema-
lionis
the
sporangia
are borne
on
branchlets
while
all
I have seen
in my species were
sessile.
These differen-
ces to which several others can be added show that my plant is
very
different from that
of DE NOTARIS.
This species has been found at the shores of St. Croix: Coakley Bay
(in Codium isthtnodadum) and S t. J a n
: Off America Hill (in Codium elongatum).
21.
Chantransia Liagorae
nov. spec.
Fila
vegetativa
endophytica
inter
filamenta
assimilatoricis
hospitis
repentia,
parce ramosa,
ramis
sparsis,
ramulis
brevibus
instructis.
1
) HEYDRICH,
F.,
Vier
neue
Florideen
von
Neu-Seeland
(Berichte
d.
deutschen
bot.
Gesellschaft, Bd. 11,
1893,
p. (78),
pi. XXII,
fig.
8).
2
) HARVEY, W.
H., Phycologia Australica,
vol. V, 1863, p. LVI; compare
also
J. AGARDH,
Epicrisis,
1876,
p.
12.
58
Cellulse subcylindricae,
dolioformes,
medio plus minus
inflates
vel interdum magis irregulares,
8
14//
latse,
ca. 35 fj. longse, chro-
matophorum
stellare,
pyrenoide
centrali
instructum
continentes.
Pili
hyalini
terminales, non numerosi,
adsunt.
Sporangia,
sessilia aut
pedicellata,
sin-
gula vel interdum bina,
globulose-obovata,
ca. 20// longa
et
ca. 14/^
lata.
This
species was
found abundantly in
Liagora pinnata.
It creeps among the assi-
milating
filaments
in
the
mucilage
and
chalk coating found here (Fig.
60).
The
filaments
are
not
particularly
branched
and
rather
long
intervals
occur
which
have
no
branches
at
all;
in
some
parts
of
the
filaments
on
the
other hand
branchlets
are
given
off
from
the
outer
side
of
nearlv
each
cell
in
the
filaments
*/
(Fig. 61).
Sometimes
these branchlets are
repeatedly ramified;
it
also happens
occa-
sionally
that two
branchlets
arise
from
the
same
cell.
These
branchlets bear the monosporangia,
but
sessile sporangia placed
immediately upon
the
cells
of
the main
filaments
are not
un-
common.
Fig.
(50.
Acrochsetium
Liagorse nov. spec. Part
of a plant between the
assimilating
filaments
of Liagora.
(About 120:1).
Fig. 61.
Acrochsetium Liagorse nov.
spec.
Parts of three plants with
sporangia (some ones emptied).
(About 75:1 and 200:1).
The
cells in the main filaments are irregular in shape, mostly
somewhat
swollen
in the middle tapering towards both ends;
in
the middle their diameter reaches a length of about 16 //,
at the
ends about
8/^;
their length varies about 35^.
The chromatophore (Fig. 62)
is stellate with long strands run-
59
ning along the walls
of the
cells;
in their middle a well developed
pyrenoid
is present.
The
cells
in
the
ends
of
the filaments bear now and then
thin hyaline hairs
(Figs. 60, 62); these
are about
5,5 // thick and
reach a length
of about 300
400 /*.
Fig. 62.
Acrochsetiwn Liagorse
nov.
spec.
Part of a plant with sporangia
and
hair.
(About 400
: 1).
As mentioned above the monosporangia are developed in the
end
of
the
branchlets
or more rarely upon the main
filaments;
they
are
obovate-globular
of
shape,
about
20 //
long and
14 //
broad.
Of
the
species
mentioned
by ROSENVINGE
I think
it comes
nearest to Acrochdstium (Chantransia) Polyidis Rosenv.
This species has only been found once at the south coast of St. Croix.
22.
Acrochsetium
ernothrix
nov.
spec.
Thallus c^spitulosus,
ca. 400 //
altus.
Pars basalis non certo
observata est.
Fila erecta a basi ramosa.
Kami principals stricti,
in inferiori parte paucis,
in superior! numerosis ramis
et ramulis
instructi.
Gellula? ramorum
5
6/^
latse
et
15
18
fj.
Ionga3,
cylindrica?,
chromatophorum zonatum prolongationibus
irregularibus instruc-
tum
et pyrenoide
centrali munitum continentes.
Ramuli
sporangiferi
e
2
3,
rarius pluribus
cellulis
compo-
siti,
ad
apicem
versus
angustati
in
pseudopila longa producti.
Monosporangia
sessilia
aut
pedicellate,
lateralia
2
3
seriatim
posita,
rarius
terminalia,
ovato-oblonga,
8
10^ longa et
5
6^
lata.
Of this characteristic species
I have only succeeded in finding
a
single specimen.
It was growing upon a Centroceras-plani
for-
ming a small
tuft.
60
As to the base
I much regret
that
I
have
not
been
able
to
state
with
certainty how
it
is
formed having only had a single
specimen.
By means
of
chlor-
zinc jodine, which coloured the
Acrochsetium
and
at
the
same
time
had
a
clearing
influence
upon
the
tissue
of
the
host
plant,
I
have
arrived
at
the
conclusion that
the
base most
probably
consists
of
a
few
creeping
filaments
somewhat
immersed
in
the
tissue
of the
host
plant.
From
this
basal
part
an
erect filament
arises which im-
mediately begins to give off bran-
ches forming in this way a small
tuft about 400 p. high. The prin-
cipal filaments are rather straight
(Fig. 63)
; they branch out in all
directions
along
their
whole
length but mostly in the upper
part. They consist of cells about
5
Qfji broad and
15
18 ju
long.
The chromatophore(Fig.64) is band-
shaped
often
with
more
or
less
long
prolongations along the wall of the
cell
;
in the
middle
a large pyrenoid
is
pre-
sent.
The branches are of two kinds, short
sporangia-bearing
branchlets
(Fig.
64)
and ordinary
branches
growing out to
filaments
like
the
principal
filaments
and
again
branched
in the same way.
The
branchlets
have
a
very cha-
racteristic
appearance
(Fig.
64).
They
consist
of two
or
three,
rarely more,
cells
the
uppermost
of
which
taper
Fig.
64.
Acrochsetium erno-
greatly and
runs out in a long hair-like
J
"--P-
Branchlet
prolongation composed of two or three,
(About 350
: 1).
Fig. 63.
Acrochsetium ernothrix nov.
spec.
Erect
ramified
filament with
sporangia-bearing
branchlets
ended
with
hairs.
(About 150:1).
61
thin, nearly colourless
cells.
The whole length
of
the branchlet
is about 80
100 //.
The
hair-like prolongations have a length of
about 50
fj. and
are about
1
2
fj.
thick
in the summit.
Upon the lowest
cells
of these branchlets we
find a single or
mostly two
or
three
serially
disposed
sporangia
(Figs. 63,
64).
The lowermost sporangia are often pedicellate, the others
sessile.
Rarely sporangia are found terminally upon
short two- or three-
celled
branchlets.
The sporangia
are
ovate-oblong,
8
10/*
long
and
5
6^
broad.
This species was gathered in a sheltered locality behind Long Reef at
Lt. Princess, St. Croix.
Subfam.
2.
Nemalieae.
Nemalion
Targioni Tozzetti.
1.
Nemalion Schrammi
(Grn.) Bergs.
BORGESEN,
F., Some new
or
little known West
Indian
Floride,
I
(Botanisk Tidsskrift,
vol. 30,
1909,
p. 4,
pi.
1).
Helminthodadia Schrammi Crn. (nomen nudum)
in MAZE et SCHRAMM,
Algues de
la Guadeloupe,
2e Edit., Basse-Terre 18707,
p. 177.
On
the
south
side
of
St. Croix
I have found some few but
large and
well
developed
specimens
of
a Nemalion
which
I
in
my
above
mentioned
paper
have
referred
to
Helminthodadia
Schrammi Crn.
For
details
I
refer
to the above mentioned paper and
shall
here only give a description
of the plant.
The
specimens
when
living
had
a
very
gelatinous
surface
so that they slipped out
of one's hand
like an
eel; on the other
hand the
consistency was rather tough.
The colour was a dark
redbrown.
The thicker main
branches which
reach
a
thickness
of about
! 1
/ 2 cm were somewhat compressed, the thinner nearly
terete.
The
surface was smooth in
places, being somewhat curled
or crisp especially in the thicker branches.
On drying they adhere strongly to the paper and gradually
take on a
dirty, yellow-brown
colour.
The plant was
fastened
to
stones
and
shells on the bottom
by means
of a small roundish
disc
at the
base.
The specimens
are irregularly ramified on
all
sides,
often too
with numerous proliferations
at the apices
(cfr.
1. c.
plate
1 ).
62
The
middle
of the thallus
consists
of a tissue
of
colourless,
rather poorly ramified,
cell-threads
which are loosely interwoven
(Fig. 65 E}
;
the
cell-threads
are from
2 to
12
/j. thick and con-
sist
of rather long and thick-walled
cells.
[((# Towards
the
periphery
these
hypha9-like
cell-threads
are
more richly ramified and here pass evenly into the
radially pla-
ced
assimilating
fila-
ments, which are arran-
ged
in
small
groups
(Fig.
654).
They
are
dichotomously
divided,
moniliform,
consisting
of
oval
cells which
are
about
28 n long and
of
about
half
that
in
breadth.
In
the
upper
end
of the cell lies the chro-
matophore, but often
it
fills
up
also
more
or
less
the
whole
cell;
it
is
irregularly
star-like,
consisting
of
numerous
strands
which
radiate
from
the
centre
of the
cell
in
all
directions
(Fig. 65 F]\ when
these
strands meet each other
at the periphery
of the
cell they grow together
and
form
a
clathrate
layer
with
large
and
numerous openings with-
in
the
cell -wall.
In
^
the
central body
of the
chromatophore
a
pyre-
noid
is
present
which was
densely stained by means
of hsema-
toxyline.
The structure
of the chromatophore seems thus to be
in good agreement with
that
of Nemalion multifidum
according
to WOLFE'S
description
("Annals
of Botany",
vol. XVIII,
1904,
p. 610) with the exception that he has not
found a pyrenoid
in
his
material.
And
further
it
also seems to agree well with that
Fig. 65.
Nemalion Schrammi (M. etS.) Bergs.
A, assimilative filaments with two carpogonial
branches (A, 140: 1). B and C, groups
of car-
pogonial branches.
(B, 160
: 1,
C, 140
: 1).
D,
cystocarp
with
decayed trichogyne
(140
: 1).
E,
colourless
cells
from
the
middle
of
the
thallus
(140:1).
F,
Two
assimilative
cells
with
chromatophore,
pyrenoid and
nucleus.
(250: 1).
63
of Nemalion lubricum according to the statement of L. KURSSANOW
in "Flora",
99. Bd., 1909
p. 311.
It
is
here
pointed out
in ac-
cordance
with
the
opinions
of
earlier
investigators and
in con-
tradiction
to WOLFE'S
statement
that
a
pyrenoid
is present
in
the middle
of the chromatophore.
Rarely
the vegetative
cells
terminate
in
a rather long hair
(Fig. 654).
Most
often the main
cell-thread
in the middle
of the above
mentioned groups
of assimilating-filaments terminate
in a carpo-
gonium
and
further
also often
2
4 or more side-branches
like-
wise
bear
terminal
carpogonia
(Fig. 65 A).
Fig. 65 C
shows
a
branch dichotomously
divided,
in which the branches terminate
in
a carpogonium.
The
carpogonial
branch
is composed usually
of
4
cells, but
sometimes only 3 occur, occasionally even
5.
This is in agreement
with Nemalion multifidum where
the number of cells also is some-
what variable.
BORNET and THURET
x
) give the number to be 3
4,
JANCZEWSKI 2
)
indicates
it
to be composed
of
3
cells and WOLFE
(1.
c., p. 613) writes:
"This carpogonic branch
is composed usually
of three
cells
;
since, however, the number varies from two, in the
simplest
noted,
to
as many
as
five,
it cannot be considered as
in any way
significant".
A well developed nucleus was found in
each
of the
cells
of
the
carpogonial branch
(Fig. 65 B}\
on the
other hand the chromatophore was not very conspicuous even
if
it was not
quite absent
as JANCZEWSKI describes
it.
The
cells of
the carpogonial branch
are roundish-subquadrangular and usually
a
little
shorter and thicker than the vegetative cells in the lowest
part
of
the
cell-thread.
By means
of
this
they
are
also most
often
easily
recognisable
though
I
must
confess
that
it may
sometimes be
difficult
to
decide
where
the
carpogonial
branch
begins and the vegetative
cells
end,
as WOLFE has
also pointed
out
in
this way concerning the carpogonial branch
of Nemalion
multifidum
(\.
c. p. 613):
"The
lowest
cell
of the
series partakes
to
some
extent
of
the
characters
of both, and thus
lessens the
abruptness
of the transition between the two types".
The
carpogonium
bears
a rather short and
often somewhat
bent
trichogyne which
is
swollen towards
its apex.
In
spite
of
x
) BORNET,
E.
et G. THURET, Recherches sur la f^condation des Floridees
(Ann.
sc.
nat. Botanique, V. ser.,
t.
7,
1SG7
p.
141).
2
) JANCZEWSKI,
E., Notes
sur
le
d6veloppement du cystocarpe dans
les
Floridees.
(Mem. de
la Soc. Nat.
d.
Sc. Nat. de Cherbourg,
vol. XX,
p. 109).
64
much search I have not succeeded in finding antheridia; occasionally
some decayed fragments of what perhaps might be remains of anthe-
ridia were found
at the
tips
of the filaments, but
it seems to me
very doubtful what they really were. Most probably the specimens
are
dioecious
in accordance with what ROSENVINGE
(1.
c.
p. 146)
has
stated to be commonly thecase with Nemalion multifidum
in
the Danish waters.
I have never seen spermatia
in contact with
the trichogyne.
Nearly,
all
the
material
at hand was found in
this
stage of
development.
In
the youngest
tips
of
the
plant
only were
no
carpogonial branches yet
developed.
After much
search
and by
taking
samples
in
different
parts
of the
dried
material
I
have
however found a few cystocarps of which fig. 65 D illustrates one.
If these
are normally constructed, the sporogenous
filaments seem
to be more loosely connected than those in Nemalion multifidum.
The carpospores are about
11
/j. broad.
This
species was
found in shallow water fixed to stones and
shells
near
the
shore.
The
locality was
rather
sheltered;
but
nevertheless small waves occur by which the plant was moved to
and
fro.
Only
collected
once in the month
of February on
the south
coast
of
St. Croix: at Long Point.
Geogr. Distrib.
: West
Indies.
2.
Nemalion
longicolle B0rgs.
B0RGESEN,
F.,
Some new
or
little known West Indian
Florideee,
I.
(Botanisk Tidsskrift
vol. 30,
1909,
p. 8,
pi.
2j.
This
species
was growing together
with
the
preceding
one
which
it
very much resembled
in
colour
and
outer habit.
For
this
reason
I
did
not
observe when
collecting the plant that
it
was
different
from N. Schrammi and
I have therefore unfortun-
ately not preserved
it in any other form than
dried.
It
was
only
during
the
microscopical
examination
here
in
Copenhagen that
it became clear that my material contained two
forms
and
after
having
arranged them
in
accordance
with the
different microscopical
characters they then showed
quite plainly
a difference
in habit
also.
Thus
the
specimens
(1. c., plate 2) when compared
with N.
Schrammi
were
found
to be more
slender, the thickest branches
being
5
7 mm
thick.
They
were
richly
subdichotomously
or
laterally
ramified
and
the
thallus had
not the
crisp folded
sur-
face to be found in N. Schrammi.
The colour of the dried spec-
65
imens was red-brown in contrast to the more dirty yellow-brown
in N. Schrammi.
As
to
the
anatomical
structure,
this
species
consists
in
the
interior
of
nearly
colourless,
long-celled,
hyphse-like,
thick-
walled cells running mostly in a vertical direction, interwoven and
from
3
14 /*
thick.
Near
the
periphery they
are more
richly
ramified and bear here the horizontal assimilating filaments which
radiate outwards in small bundles and branch dichotomously (Fig.
66 A).
Innermost
at
the
transition
from
the
medullary
tissue
the
cells are rather long and nearly cylindrical but they grow soon
shorter
and
at
the
same
time
become
swollen
in
the middle
in such a way
that
the
cell-threads
be-
come moniliform, reaching
a thickness
of about
13
14^.
Compared
with
N.
Schrammi
the
cells
are
somewhat
slender.
The
chromatophore
(Fig. 66 C)
is
stellate and
resembles very much that
of N. Schrammi though
as
a general rule
it only
fills
half the
cell
;
of the outer-
most
ones
nearest to
the
.
i
,
Fig. bb. Nemahon longicolle Borgs. A, bundle
periphery
it occurs at the
Of assimilative
filaments
in the middle
of
top,
while
it
is
found
in
which
the cystocarp (140
: 1).
B, another
i
,
., n
cystocarp
(140:1).
C,
cells with chroma-
tne
middle
ol
the
tophore and pyrenoid (250
: 1).
D, carpo-
slender
and
more
cylin-
gonial branch with trichogyne
(140
:
1).
drical
cells further in.
In
the middle
of the chromatophore a pyrenoid
is present.
Having
only dried material for examination
I have not succeeded in finding
the nucleus.
In the middle
of
each
of
the
peripheral bundles
of
assimil-
ating filaments
a
single
cystocarp
occurs
(Fig. 66 A, B);
it
is
very rarely that a second one
develops on a side-branch.
While
in
N. Schrammi
nearly
all
the
material
was
in the
stage
of development mentioned above,
viz. with the trichogynes
still
present,
in
Nemalion
longicolle
nearly
all
the material had
ripe
cystocarps.
These
are
terminally
placed
on
a
rather long
straight branch, the cells of which are shorter and nearly cylindrical,
66
grading rather evenly over into the
cells belonging
to the carpo-
gonial branch
; sometimes also as shown in
fig. 66 A the growth of
the branch has stopped and a side-branch has then grown out
as
a prolongation
of the mother-branch bearing the cystocarp.
The
carpogonial
branch
is composed
of
4
6
cells;
these
are
shorter
than
the
vegetative
ones
and
contain only a
slightly developed
inconspicuous
chromatophore
or
only
remains
of
it.
The
cell-
walls of
the
carpogonial branch are
distinctly stained by heema-
toxyline.
The
cells
in the carpogonial branch are about 9// thick.
In
the
youngest
tips
of
the
plant
some
younger
carpogonial
branches occurred and a few with trichogynes
still preserved were
found
in
the
older part
of the thallus perhaps because they had
not been
fertilized
;
the trichogyne had nearly the same form as
in N. Schrammi, growing thicker towards the
tip
(Fig. 66 D}.
The carpospores were about
14// long and 11^ broad.
As
to
the
outer
habit,
I may add that
near
the base the
thallus grows
at
first
thinner but
finally
it
broadens
out
again
to a
small
disc, by means
of which the plant
is fastened to stones
and
shells on the bottom.
The plant was growing
in shallow water quite near the shore
in rather sheltered
localities where
it swings to and fro following
the feeble motion
of the
sea.
It was
collected
in the middle
of
February having at that time
ripe
or nearly ripe cystocarps.
Only found once on the southern coast of St. Croix:
at Long Point.
Liagora Lamour.
As
is
well known
J. AGARDH
has
given
a
survey
of
the
anatomical structure
of the species
of Liagora.
The
title
of
his
paper
is:
"De
differentiis
in
structura
frondis,
quse in
diversis
Liagorgg speciebus observantur" (in "Analecta Algologica", Conti-
nuatio
III, Lund
1896,
p.
96).
This
paper does not seem to be
quite
satisfactory
most
probably
because
J. AGAEDH
had
not
sufficient material and has based his description exclusively upon
dried
material.
Several
of
his
species
seem
to
be
so
closely
related that they most probably belong to one another being forms
of the same
species.
In
any
case
it
is not always an easy task
to determine by means
of
J. AGARDH'S description a Liagora-spec-
imen. A monograph of this genus would certainly be of much use.
) has promised such a work, but up
till now he has merely
1
) ZEH, W., Neue Arten
der Gattung Liagora (Notizblatt des
Konigl. bo-
tanischen Gartens und Museums zu
Berlin.
Band V,
1913,
p. 268).
67
given
short diagnoses
of some new species, which has only added
to
the
difficulties.
Having now examined my West Indian ma-
terial
of
this
genus
I have found that good characters are pre-
sent not only in the shape
of the assimilating filaments but also
in that
of the carpogonial branch,
of the antheridia and the cysto-
carps.
In the last mentioned, especially, the filaments surrounding
the sporogenous filaments are very differently developed.
In the
specimens
which
are
not
easily
recognizable
by
means
of
the
external
habit,
e.
g. rami-
fication,
calcification
etc.,
these characters of internal
structure might be of great
assistance.
Judging from the
de-
scription of BUTTERS l
) Lia-
gora reminds one much of
Trichogloea,
the
essential
difference is that the carpo-
gonial branch
is
lateral
in
Liagora,
and
terminal
in
Trichogloea.
1. Liagora elongata Zanard.
ZANARDINI,
G.,
in Flora,
vol.
34,
1851,
p. 35;
Plant,
in
Mari Rubro
.
.
.
(Memorie
Isti-
tuto Veneto,
vol. VII,
1857,
p.
274,
tab.
6,
fig.
1).
KUTZING,
F.,
Tabula? Phycol.,
vol. VIII,
1858,
pi.
94
II.
AGARDH,
J.,
Epicrisis, p. 516; AnalectaAlgo-
logica,
Contin.
Ill,
p.
105.
Fig. 67.
Liagora elongata Zanard.
Part of
a plant.
(About 3:1).
As
pointed
out by
J. AGARDH
(1.
c. p. 105)
this
species
is
characterized by the
fact that the
cells in the robust assimilating
filaments
(Figs.
68, 69 a)
have
nearly the same breadth through
their whole
length and
further
that the
cells are seldom longer
than
double
their
diameter.
The
assimilating filaments are not
much ramified
; the branches
arise mostly at an acute angle from
the mother filaments and are
all
straight or nearly
so.
l
) BUTTERS, FR. K., Observations on Trichogloea
lubrica.
(Minnesota Bo-
tanical
Studies, Third
Series, Part
I,
1903,
p.
11).
68
The
lowermost
cells
in
the
assimilating filaments
are
larger
and
often
somewhat
irregularly shaped
;
their
breadth
is about
40//;
higher up the
cells grow thinner, about
17// and keep this
diameter almost
until the apex.
The whole assimilating filament
reaches a length
of about 400
500/2.
The medullary
cells are
large subcylindric-barrelshaped, their
diameter reaching a length
of up to
150//
or more and the whole
length
of the
cells about ten times the breadth.
With a trans-
Fig. 68.
Liagora elongata Zanardini.
a, assimilating filaments with
hairs and
(b) with antheridia.
(a, about 140
: 1,
b 60
: 1).
verse section
(Fig.
70) one
sees that they are not
lying close to-
gether
in
any
case
not
after
decalcification,
but imbedded
in
mucilage,
and
in
this
irregularly bent
thin
filaments run
in
all
directions
;
these
last mentioned
filaments consist
of long nearly
cylindrical
cells, the diameter of which is about 8
10// and
their
length about
10 times
the
breadth.
These thin filaments have
their
origin
from
the
large
basal
cells
in
the
assimilating
fila-
ments.
From
nearly
all the summits
of the young assimilating
fila-
ments
long
hairs
arise
(Fig. 68);
these
are about
5
(
thick,
in
their
uppermost
somewhat
swollen end
about
8//
and
reach a
69
length
of about 250^.
They
are
quite
hyaline with the excep-
tion
of
the uppermost
end
which
is
almost
entirely
filled with
protoplasm.
The calcareous
layer
is
rather
thick,
but
uneven
and
loose
;
it extends from
the
medullary
tissue
to
about the upper third part
of the assimilating filaments
which are free and protrude
freely
together
with
the
antheridia and
hairs
found
here.
The antheridia (Fig. 69)
are
found
on
the
summit
of the assimilative filaments
and form dense hemispheri-
cal
or
pyramidal
clusters.
The
development
of
the
antheridia takes place as fol-
lows (Fig. 69)
: The end of an
Fig. 69.
Liagora elongata Zanard.
a, me-
dullary
cell
with
assimilating
filaments
and
antheridia.
b and
c, development of
antheridia;
d,
e,
nearly
ripe
antheridia,
e,
in transverse section,
(a, about 60
: 1,
b,
c,
d,
e about 300
: 1).
assimilating
filament which
is
at the same time rich on
contents is prolongated coni-
\
cally and divided by
trans-
verse
walls
into
several
small cells
; from these again
small
conical
outgrowths
arise
on
all
sides
which
soon
are
divided by transverse walls
(Figs. 69 b,
c)
giving
rise to small branches.
These
are
repeatedly
di
trichotomously
branched
into
several
small
branchlets,
the
end
cells
of
which
are
the
antheridia
(Fig. 69 e).
In
the
material
collected
I
have
only
found antheridial plants
;
so
I
cannot
give
any information
as to the carpogonial branch
or cystocarp.
Forms
of
this
species
have
been
fre-
quently
referred
to
the
Australian
plant
Liagora
Cheyneana
Harv., a species which
also shows not a
little likeness to Liagora
elongata.
Fig. 70.
Liagora elon-
gata
Zanard.
Trans-
verse
section
of
me-
dullary tissue. (About
60:1).
70
This species
has been found in the month
of February near
the
shore
in shallow water in a somewhat exposed
place.
St. Groix:
Long Point.
Geogr. Distrib.
:
Red Sea, Mauritius,
Florida, West
Indies.
2.
Liagora corymbosa
J. Ag.
AGARDH,
J., Analecta Algologica, Contin.
Ill, 1896,
p.
104.
Of
this
plant
I
have
had
only
a
single
dried specimen
at
my
disposal.
This specimen agrees well with
the
few
found
in
J. AGARDH'S Herbarium
at Lund.
The plant has a rather characteristic appearance
;
it
is reddish
brown when dry and has
a very scabrous surface which examined
under
a dens
is
found
to be composed
of dark red and whitish
dots.
The ramification
is irregularly dichotomous with numerous
prolifications,
the branches spreading out at nearly right
angles.
Having had
only
dried
material
I
shall
not enter upon
a
more
detailed
description
of
the
anatomical
structure but only
point out that
it seems
to agree closely with that
of L. elongata.
The
cells
in the
assimilating filaments
are nearly cylindrical or a
little
barrel shaped, about
2
3 times
as long as broad and about
17^
thick.
The antheridia
also seem to agree exactly with those
of L. elongata. Most probably therefore this species is only a variety
of that plant.
ZEH, who has had
the material
in the Botanical
Museum. Copenhagen, for determination, has named the specimens
of this
alga as L.
elongata.
This plant has only been collected
as washed ashore material
and was sent to me by Dr. HAMBURGER.
St. Croix:
Sandy Point.
Geogr. Distrib.:
Florida, Bermudas.
3.
Liagora
valida Harv.
HARVEY, W.
H., Nereis Bor.-Am., Part
II,
1853,
p.
138,
tab.
31, A.
AGARDH,
J.,
Epicrisis,
p.
517;
Analecta
algologica,
Contin.
Ill,
p.
107.
KUTZING,
F., Tab.
Phycolog.,
vol. VIII,
pi. 92
I.
This
species
was
originally
described
on
specimens
from
Florida,
and
judging
from
HARVEY'S
clear description my spec-
imens seem to agree well with them.
The plant
is
characterised
by
having
a
terete
frond
(about
1 mm
thick)
which
is
fairly
regularly dichotomous. The calcareous coating
is quite continuous
giving the plant an even surface and when dry a whitish colour
;
71
only
in the summits
of the frond
is
it not
so complete
allowing
the
red-brown
tips
of
the
assimilating
filaments
to
protrude.
Also
the
cystocarps
project
above the calcareous
layer and
are
seen in the fruiting specimens as dark red dots (comp.
fig.
71).
The assimilating filaments have, as pointed out by J. AGARDH,
a corymbiform
outline
(Fig.
72).
They reach
a length
of about
200 p.
or
somewhat
more.
They
are
4
5
times
repea-
tedly forked.
The uppermost
cells are pearshaped or broad
oval,
about
10
12 //
thick
(Fig. 73 b)
;
lower
down
in
the
filaments
the
cells grow
longer,
at
length
becoming
subcylindric.
The lowermost
cells
are about 16^ thick.
The
central
filaments
consist
of
subcvlindric
cells
t;
somewhat
tapering
towards
the ends
(comp.
figs. 72 and
74 a)
; they are about 2040^
thick or more, and often reach
a length up to
20
times
their own
diameter.
They
have
very
thick
walls.
Between
these
thicker
filaments
run
thinner ones
(lat.
about
8/*),
as
the
transverse
section
of
the
medullary
tissue
shows
(Fig.
74).
These
thin
filaments
originate
from
the
lower-
most
cells
in the assimila-
ting
filaments
(comp.
fig.
75 a).
They
run
between
or creep along the medul-
lary
filaments
;
and
from
those
near
the
surface
erect filaments arise (comp.
fig. 73 a).
They are somewhat branched and consist of oval cells
;
they grow up between the
assimilating filaments.
As they have
well developed chromatophores they may be considered as a kind
of secondary assimilating filaments.
The carpogonial branch
is borne upon one
of the cells
in the
Fig.
71.
Liagora valida Harv.
Part of a plant.
(About 3:1).
Fig.
72.
Liagora valida Harv.
Assimilating filaments with carpogonial
branches.
(About 60
: 1).
72
middle
of
the
assimilating filaments
(Fig.
72).
Besides the
car-
pogonial
cell with
the
trichogyne
it
consists most commonly
of
4
cells
(Fig. 75 6), sometimes
of
3
only.
The branch
is compara-
tively thick, the diameter reaching often
a length of 22//.
After
fecundation the carpogonial
cell
is divided by a
transverse
wall
into two
cells from the uppermost
of which the sp erogenous
fila-
ments grow out
(Fig. 75 a),
while the lowest remain undivided.
The cystocarp (Fig.
75 c)
is a comparatively
large
spherical
body
which reaches often more
than 400
[j.
in diameter.
It consists of thin sporo-
genous
filaments
(lat.
about
8//);
these
are
ramified,
more
or
less
woven
together
and
composed of rather long
nearly subcvlindrical
Or
Fig.
<3.
Liagora
valida
Harv.
a,
assimila-
J
ting filament (comp. the
text),
b,
Part
of a
more
irregularly shaped
filament showing shape of the
cells,
(a, about
cells
At the end of the
60
: 1;
b, about 160: 1).
filaments the carpospores
are produced
(Figs. 75 d,
e)\
these reach a length
of about 10^
while
their
diameter
is
about
5
6^,
After the
fertilization
of
the
carpogonium
several
ramified
filaments
arise
from
the
cell
below
that
upon
which
the
carpogonial
filament
is
inserted.
These
pericarpic
filaments
consist
of
thicker,
oval,
often
nearly
spherical,
sometimes
also
more
irregularly
shaped
cells
;
they grow up-
wards around the cystocarp.
Furthermore from
the basal part
of these
cells and also from the
sporogenous
filaments
thin
hair-like
filaments
grow downwards often
in
great numbers
(Fig.
75
c).
The
antheridia
I
have
not
found
in my material
;
on
the
other hand
they
were
present
abundantly
in
a
specimen
from
Key West, (FARLOW, ANDERSSON & EATON, Alg. Am. Bor.
exsicc.,
no. 70)
in Herb.
J. AGARDH
in Lund.
The antheridia are found
on
the
summits
of the
assimilating
filaments
whose uppermost
cells
are
divided
into
thin
filaments
in
the
end
cells
of which
the spermatia are developed.
?
Fig. 74. Liagora va-
lida Hary.
Trans-
verse section of the
medullary
tissue.
(About 60:
1).
73
Liagora tennis
J. Ag. seems to come very near to this species
judging
from
the
few specimens
upon
which
J. AGARDH
based
his
description.
Compared
with L.
valida
the thallus
seems
to
be
a
little
thinner,
but except
for
this not very
essential
diffe-
rence
they
are
very
alike.
Of
one
of the
specimens,
collected
at Florida by Miss CURTISS a small piece was examined;
it had
the
assimilating
filaments less rami-
fied than in L. va-
lida
and
the
fila-
ments had not the
corymbiform
out-
line, but to decide
how
far these
dif-
ferences
are
other
than
casual
de-
velopment
much
more
material
is
necessary.
Liagora
annii-
lata
J.
Ag.
also
seems to come near
to
Liagora valida;
/b
indeed, most
pro-
Fig
.
75.
Liagora
valida
Harv.
a, assimilating fila-
bably,
it
is
only
ment with young
cystocarp,
b, carpogonial
branch,
t
f
th*
C)
cys tocarp with surrounding filaments,
d,
e, sporo-
a
variety
01
tnis
genous
filaments
with
carpospores.
(a and
c about
species;
a
suppo-
60:1;
6,
d, 160:1;
c, 140
: 1
;
e,
250:1).
sition
I have con-
firmed by the
fact that
in some
of my specimens now and
then
a rudimentary annulation
is present.
But to
settle this question
rich
material
is
necessary.
In
his paper,
"Notes
on Bahaman
Alga?
1
)", HOWE
considers
it
as a
distinct
species.
Liagora
valida
has
been
collected
with
ripe
carpospores
in
January and February.
It grows
in shallow water
in the upper
sublittoral region and
in somewhat sheltered
places.
St. Croix:
At White Bay near the south west end of the island and
at Coakley Bay upon the north
side.
Geogr. Distrib.
:
West
Indies, Madagascar.
Bulletin of the Torrey Bot. Club,
vol.
31,
1904,
p.
99.
74
4.
Liagora pinnata Harv.
HARVEY, W. H., Nereis Bor. -Americana, part II, 1853, pag. 138. AGARDH,
J.,
Epicrisis,
1876, pag. 517; Analecta Algologica, Contin. Ill,
1896,
p. 108.
The
plants
(Fig.
76)
I have
referred
to this species seem to accord well with the
description and
figures
of HARVEY
(1.
c.)
even
if they show some
differences.
HARVEY describes the frond
as three
inches long
; my specimens reach
a length
of
up
to
16 cm.
The
stems
are
set
at
short
intervals
with
branches,
spreading
out on
all
sides
longest
in the middle
of
the
frond,
shorter
upwards
and
down-
wards.
These branches bear again branch-
lets
placed
in
the same manner and the
branchlets
again
ramuli.
HARVEY
says
o? f "lanf?
that the ramuli
are "o ften opposite" but
(About 3
:
1).
this does not agree with my observations.
For
the
rest
I
refer
to
HARVEY'S
good
description
of
the
dried
plant;
his
comparison
of
the
very uneven
surface
with
"pepper
and
salt"
is
very
strik-
ing
,
darker
red-
brown
dots
protru-
ding over the whitish
coating
originating
from
the
upper
end
of
the
assimilating
filaments
and
cysto-
carps.
The central nearly
or
quite
colourless
filaments in the thai-
Fig.
77.
Liagora pinnata
Harv.
a,
assimilating
,
t
f
1
filament
with
carpogonium
and
antheridia,
b,
on
part of an assimilating filament with
antheridia
more
or
less
cylin-
(a, about 60: 1;
b, 160: 1).
drical
cells
tapering
usually somewhat near
their
ends
(Fig. 77 a)
;
these
cells
are
about 50/^
thick and about
8 times their own length; but some
75
occur which
reach more
than
100
ft
in diameter
;
besides
these
cells there are many
of
a much more irregular form.
The
assimilating
filaments
(Fig. 75 a)
consist
at their base of nearly cylindric
cells
about 40^ thick and
2
3 times
as long as
broad.
The
filaments
branch several times
(45 or more)
the
cells
at
the
same
time
becoming
gradually
thinner,
the
thinnest
being
found
somewhat
over
the
middle
of
each
cluster
of
filaments
;
then
they grow
thicker again
until near the top where they
suddenly
narrow
conically.
In
the
cluster
of
filaments
represented
in
fig. 77 a
the
cell
at the base
is
thick,
the
thinnest
cells
in
the
middle
of
the
cluster
are 11
(
and the thickest near the top
25 p.
Fig. 78.
Liagora pin-
nataHarv. Transverse
section
of
medullary
layer.
(About 60
: 1).
Fig.
79.
Liagora pinnata Harv.
a, carpogonial branch,
b,
c,
d, development
of the cystocarp,
(a and b, about
160:
1,
c and d 150: 1).
From
the
basal
cell, and sometimes
also from other
of the
lower
cells
in the
cluster of assimilating filaments,
rhizoidal
fila-
ments grow
out along the
central
large filaments (77 d).
These
rhizoidal filaments consist of long more or less cylindrical or some-
what
inflated
cells
;
from
these
erect
filaments
grow
up
the
cells
of which
are
shorter but often rather thick,
oval
or rather
irregularly inflated, the filaments
in this way getting a somewhat
moniliform appearance
; these filaments become
intermingled
be-
tween the
assimilating filaments
of the periphery.
Somewhat below the middle
in the cluster of the assimilating
filaments
we
find
the
carpogonial
branch
(Fig. 77 a).
This
is
placed
laterally upon one
of the cylindrical cells found
here, and
76
is
as
a
rule
composed
of four
cells
:
three
cells and the carpo
-
gonium with
a
rather
long
thin
trichogyne
(Fig.
77
a).
After
fertilization
the
carpogonium
is
divided
by
a
transverse
wall
into
a
basal
cell, which
as
is the
case
in Nemotion
and
Hel-
minthora,
remains
undivided,
and
an
upper
cell.
This
cell
is
firstly
divided
by
a more
or
less
vertical
wall
into
two
cells,
after which
variously
orientated
walls
arise (Fig. 79 &,
c, d), the
Fig.
80.
Liagora pinnata Harv.
Cystocarps.
a, with sur-
rounding
filaments,
b,
showing
carpospores.
(a,
about
60: 1,
b,
150:1.)
result
of which
is a
cluster
of irregularly bent, ramified filaments
(Fig. 80 a).
These
are
the
sporogenous
filaments whose
cells
at
the
end
of
the
filaments
produce
the
carpospores
(Fig. 80 b).
When ripe these
are oval or obovate, about
15 fjt broad and
18// long.
As
a
secondary
result
of
fertilization
sterile filaments begin to grow out from the
cell
immediately
below
the
cell
in the
assi-
milating branch upon which the
carpogonial
branch
is
found.
These
filaments grow up
round
the
cystocarp
forming
a
kind
of
co-
vering about
it but only very loose and im-
perfect
(Fig. 80 a).
The antheridia (Fig. 81) are found in the
same
plant
as
the carpogonial
branch
and
often
in the same assimilating filament
(Fig.
77 a).
They are placed
at the summit
of short branchlets grow-
ing
out
from
one
of
the
cells somewhat
below
the top
of the
assimilating
filaments
(Fig. 77 b}.
From the upper end
of these
branchlets ramified
filaments,
consisting
of rather short
cells grow
out
forming
dense,
nearly hemispherical
clusters.
The terminal
Fig.
81.
Liagora pin-
nata
Harv.
Antheri-
dia.
(About 170: 1).
77
cells
of
these
branchlets
are
the
mother-cell
of
the
spermatia.
The
cells
- have
a
rather
thick
wall
and
are when
ripe
about
3
4//
in diameter.
This
species was
found
in rather exposed
localities down to
a
depth
of
about
ten
meters,
It
was
collected
in the months
January and February and was
in a fructifying condition.
St. Groix:
White Bay, and near Buck Island
in
a
depht
of
about
5 fathoms.
Geogr. Distrib.
:
Florida, West-Indies.
5.
Liagora megagyna nov.
spec.
Frons
csespitosa,
12
14 cm
alta,
teres,
e
basi
sensim vix
attenuata,
irregulariter ramosa, ramis inferioribus longioribus,
su-
perioribus brevibus ramulos parvos obtusos irregulariter dispositos
gerentibus.
Crusta calcarea in specimine exsiccata farinaceo-scabrida.
Axis
centralis ex filamentis crassioribus cellulas subcylindrice-
dolioformes continentibus et filamentis tenuioribus, compositus
est.
Stratum periphericum ex filamentis dichotomis,
cellulas sub-
cylindricas
ad
apicem
ver-
sum
oblonge-ovales
conti-
nentibus compositum
est.
Kami carpogonii robusti,
recti aut
fere
recti, ex 3
5
cellulis
brevibus
compositi.
Cellula
carpogonica
brevi-
ter
conica
in
trichogynum
longum
cylindricum
pro-
ducta. Cystocarpia fere sphse-
rica
ex
filis
carposporiferis
composita,
plus
minus
fila-
mentis sterilibus, ex
cellulis
infra ramos carpogonii ortis,
circumcincta.
The ramification of this
species
is
very
irregular,
sometimes apparently mono-
podial,
sometimes
more
or
less
dichotomous with many proliferations
(Fig. 82).
The frond
is
terete and
the
calcification well developed
for-
ming a continuous covering
; only at the summits of the branches
Fig.
82.
Liagora megagyna nov. spec.
Part of a plant.
(About 3:
1.)
78
is
the
calcification
nearly wanting.
The
surface
is
glabrous,
in
dried specimens uneven
or dotted.
The
fascicles
A
of assimilating fila-
ments
b,
c)
(Fig. 83
a,
are
propor-
tionally
large and
richly ramified. The
lowermost
cells
in
each
fascicle
are
large,
somewhat
swollen
upwards,
but
very
variable
in
size,
their
dia-
meter often
reach-
ing a length of 40^
or more.
From these ba-
sal
cells
2
3
or more
filaments
grow
upwards
;
these
are
several
times di- or tricho-
tomously
divided.
The lowermost cells
in
these
filaments
are
subcylindrical
or nearly so;
after
each
division
the
cells grow
thinner
and
also
shorter
until
about
the
middle of the whole
branch
system
where the
cells on
an average are only
1015
fjt
thick.
From
here
the
cells
again
get
thicker and
at the same time
also
shorter, nearly oval, the ends
of
the
assimilating
filaments
in
this way
getting a moniliform
appearance.
The
cells
in the upper part
of the
assimilating fila-
Fig. 83.
Liagora megagyna
nov.
spec,
a,
b,
c,
d,
assimilating filaments with carpogonial branches and
hair-like filaments,
e, ends
of assimilating filaments
with remnants of died
cells,
f, g, end of assimilating
filaments with
short
hairs,
(a,
b,
d,
about 60
:
1,
c,
e,
f,
g, about
160: 1.)
79
Fig. 84. Liagora mega-
gyna nov.
spec.
Transverse section of
medullary layer.
(About 60:1).
ments
are
about
19
20 p
thick and 3035^
long.
The whole
fascicle reaches a length
of up
to 500
600 //.
Peculiar
hairlike
organs
arise
everywhere
in
the
filaments
(comp. Fig. 83
a,
c,
d).
These are short, con-
sisting of a
single cell only,
or longer, some-
times
ramified,
and composed
of cylindrical
cells whose diameter
is
5
8
(
.
The
upper-
most
cells
in these filaments
are almost
en-
tirely
filled
with
protoplasm
;
whatever
the
reason may be the whole contents
are
often
evacuated
from
the
cells and found mostly
as
a spherical but sometimes
also more irre-
gularly
shaped body at the end
of the
fila-
ments
(Fig. 83
c).
Something
quite
similar
often
takes
place
also
in the
cells
at the summit
of the assimi-
lating
filaments;
here
also now and then the whole contents
of
the cells are emptied through
a hole in the top of the cell;
remnants
of
a
membrane
originating from
such emp-
tied
cells
are
often
found
in the
end
of the
assimila-
ting
filaments
(Fig. 83
e).
Here
also
short
hairs
are
often
found
(Fig. 83
/, g),
reminding one of those which
ROSENVINGE
has
found
in
Nemotion. They are entirely
filled with protoplasm
; when
they
die
remnants
of
the
walls remain
at the end
of
the
cell.
The
central
filaments
consist of long subcylindrical
barrelshaped
cells,
whose
diameter
reaches
a
length
of 100
160^
or even more
(comp.
fig. 83
a,
b).
Along
and
between
these
thicker
filaments smaller ones run
irregularly in the mucilage
;
they
ori-
ginate from the basal
cell
in the
peripheral filaments and consist
of long cylindric
cells about 150 // long and 11^
broad.
Fig. 84
shows a transverse section
of the medullary
layer.
Fig.
85.
Liagora megagyna
nov.
spec.
Development
of
the cystocarp (comp.
the
text),
(a,
b about 160
: 1,
c about
60:1).
80
In
about
the
middle
of
the
assimilating
filaments
vigo-
rous carpogonial
branches
are
found
(Fig. 83
a, b,
c)
;
these
are
nearly
straight
and
placed
laterally
near
the
upper end
of the
almost
cylindrical
cells
found
here.
Besides
the
carpogonial
cell with
its long trichogyne,
it
consists
of
three
or
four,
rarely
five
cells.
These have rather thick walls,
are mostly shorter than
long and
a
little swollen
in
the middle
; their diameter reaches a
length
of
about
20
27^,
The
shape
of the carpogonial
cell
is
short
conical
;
it
has
rather
thick
peripheral
walls.
The
full
grown trichogyne
is nearly cy-
lindrical,
often somewhat
irre-
gularly bent towards the sum-
mit, and a
little thicker here;
when
young
it
is
seen
as
a
short obovate outgrowth from
the
carpogonial
cell,
later, on
gradually
growing
longer,
it
assumes
a clavate appearance
and
becomes
at
last
nearly
cylindrical.
Having only found a very
few fertilized carpogonia show-
^^^^^^
ing
later
stages
I
have
not
been able to follow the development in more detail.
The youngest
stage found
is shown in
fig. 85 a
; we
see here the outgrowth
of
the
sporogenous
filaments.
Fig. 85 b
shows
a
more
advanced
phase
and
in
fig. 85 c
is
portrayed
a nearly ripe cystocarpium.
As
is
the
case
in
other
species
so
here
the
fertilization
of the
carpogonium
exerts
an
influence upon
the
cell
from which the
carpogonial
branch
is
issued
and
also upon
some
of
the neigh-
bouring
cells;
from
these
numerous
filaments
grow out more
or
less surrounding the basal part
of the
cystocarp.
Vegetative filaments were found
several times
in this species
growing out from not
fertilized carpogonial branches.
Such out-
growths were
either
lateral from the
cell below the carpogonium
(Fig. 86 c)
or terminal from the carpogonium
itself (Fig. 86 d).
In
this
species
I have not succeeded
in finding antheridia.
This plant has only been found once in shallow water at Long Point
at the south coast
of St. Croix.
6.
Liagora pulverulenta
C. Ag.
AGARDH. C., Species Algarum, 1821
2,
p. 396.
AGARDH,
J., Epicrisis,
1876,
p. 516; Analecta Algologica, Continuatio
III,
1896,
p. 101.
Fig. 86.
Liagora megagyna
nov. spec.
a,
b,
development
of
the trichogyne.
c,
d,
carpogonial branches
producing
vegetative
filaments,
(a,
b,
d,
about
160:1,
c, 60:1).
81
The specimens
I have
referred
to
this
species have a
more
or
less
re-
gular dichotomous
ramification but at
the
same
time
a
good
many
proli-
ferations
are
pre-
sent
(Fig.
87).
The
assimila-
ting filaments (Fig.
'
88 a, b, c)
are
re-
latively
short,
about
300 p.
long;
they are 5
6 times
forked
and
their
outline
is corymbi-
Fig.
87.
Liagora pulverulenta
C. Ag.
Parts
of two
specimens from Rust up
Twist.
(About 3:1).
form.
In the lower part
of the filaments the
cells
are subcylin-
drical, about 9
12 p thick;
higher
up
they
become
very
thin
their
diameter
varying
from
3
6 ^
;
to-
wards the summits
of the
filaments they rather sud-
denly
grow
shorter
and
at
the same time
thicker,
oval
or
in the uppermost
part nearly spherical, their
diameter reaching a length
of up
to
12//.
The
cells
in the summits of the young
assimilating filaments often
have long thin hyaline hairs
whose
length
sometimes
reaches
double
that
of
the
assimilating
filaments.
When
young
these
hairs
Fig.
88.
Liagora pulverulenta
C. Ag.
are clavate with much pro-
a, assimilating filament,
b, part of the same
tnn
i asrn
Psr>pHallv
in
the
with a
hair,
c,
assimilating
filament with
carpogonial
branches,
d, e, f, young
hairs,
thickened
end
(Fig.
88
iL
(a, about
140:1^200:1;
c, 60
1;
d,
e,
^ ^
.
later
thpy
6
82
elongated
and
cylindrical
with
very
little
parietal protoplasm.
From the lowermost
cells
in the assimi-
lating
filaments
some
thin
filaments
arise
(Fig. 88 c)
running
along
and
between
the
central
filaments
;
they
are
branched
and
consist of rather long nearly cylindrical
cells
Fig
89.
Liagora pul-
whose
diameter
is
about
11 a.
From these
verulentaL. Ag. Irans-
'
.
verse
section
of me-
erect
lilaments with
oval
cells
occasionally
dullary tissue. (About
grow upwards between the
assimilating
fila-
ments (comp. Fig. 92
).
The
filaments
of the medullary tissue are subcylindric-barrel-
shaped
;
their diameter reaches a length
of about 100 //
or more;
in the mucilage be-
tween
these
large
filaments run many
thin ones
;
Fig.
89
shows
a
transverse
section
of
the
me-
dullary
tissue
in
which the large cells
and
the
thin
fila-
ments
are
seen,
in
their respective pos-
itions.
The carpogonial
branch
is
found
nearly in the middle
of
the
assimilating
filaments (Fig. 88 c).
It is placed laterally
upon one of the near-
ly
cylindrical
cells
found
here.
It con-
sists
of
three
cells
and the carpogonium
with the triohogyne.
It
is
characterized
by being much cur-
ved, the
outline
of
the
whole
branch forming
nearly a
semicircle and
its
cells
seen
from the
side
having
nearly a triangular
shape
;
their
diameter
Fig. 90.
Liagora pulverulenta
C. Ag.
Development
of
the
cystocarp.
(a,
b about 160:1;
c, 150:1;
(I 140
: 1).
83
reaches a length
of about 1214^.
The carpogonium
is
conical
and passes evenly into the long trichogyne.
After
the
fertilization
(comp. Fig. 90)
the
sporogenous
fila-
ments
grow out.
These
are
repeatedly branched
and
form
to-
gether
a spherical
rather
compact body.
In the summit
of the
filaments the carpospores
are developed.
Apparently even before
fertilization,
or
in
any
case
before any
visible
cell division
has
taken
place
in
the
carpogonium,
filaments
begin
to
grow
out
from the
cell underneath that upon which the carpogonial branch
is
placed
and
these
filaments
are
often considerably developed
before
the
division
of the carpogonium has begun
(Fig. 90 a, b).
In
the
more
developed
carpogonium
they
grow
longer
being
several
times
forked
and
bent
inward
and
they
more
or
less
surround
the
young
cystocarp
(Fig.
90
c);
in
the
mature cystocarp on the other hand
they
are
present
like
a whirl
of prominent
filaments
at
its
base, and have the appear-
ance
of a
collar
thus
giving the cystocarp a
very characteristic aspect
(Fig. 90 d).
The antheridia are developed in the ends
of
the
assimilating filaments
as quite
small
oblong
cells;
they
are 2
3//
thick.
In the
material
at hand they were only present
in
very small numbers.
I
have not found
an-
theridia and cystocarps together in the same
plant.
The
above
description
is based upon material
in
spirit sent
to me by Mr.
0. HANSEN GANNESKOV
and
collected at Rust up
Twist on the north
side
of
St.
Croix.
Other
specimens
which
I
also
refer
to
this
species
show
a few
differences.
They were gathered
in Lime Tree Bay on the
south
side
of
the same island where
I found them growing epi-
phytic upon
Udotea
flabellata
in shallow water.
Fig.
91
shows
that the plant was a
little more robust than
the
first
described
and the
proliferations more regularly forked.
The assimilating filaments (Fig. 92 6, c) had nearly the same size and
shape, but the uppermost
cells
in the filaments were more sphe-
rical often nearly globular.
The
few carpogonial
branches
(Fig.
92 d)
found were
curved
in
the same way,
but
they contained
only
two
cells
besides
the
carpogonium which was
very long.
Neither more
developed
carpogonia nor
cystocarps were present
in the plant.
6*
Fig.
91.
Liagora pul-
verulenta C. Ag.
Part
of
a
plant.
(About
3:1).
84
Some
few
other
dried
specimens
I
have
also
with
some
doubt
referred
to
this
species
;
but
having had only dried and
scanty material
I shall not enter upon a description of them.
In
this connection
I
also want to
point out that
it
is possible that
some
of
these
belong
to
L. leprosa
J. Ag. How
far
this
species
is anything
else than a form
of L. pulverulenta
I am not able to
Fig.
92.
Liagora pulverulenta
C. Ag.
From Lime Tree Bay.
a,
basal part
of
assimilating filament
icomp.
the
text,
p.
82).
b,
assimilating
filament.
c, assimilating filaments ended with long hairs,
d, part of assimilating fila-
ment with carpogonial branch,
e,
antheridia.
(a.
c,
d, about 140
: 1
;
b,
60: 1;
e, 170:1.)
decide.
I am strongly inclined to think that the anatomical
dif-
ferences
between
the two
species
mentioned by
J. AGARDH,
are
merely accidental.
During a
visit to Lund
I had opportunity to
examine the specimens
in
J. AGARDH'S Herbarium and
have not
been able to confirm his observations.
In a paper: "Notes on the
species
of Liagora and Galaxaura
of central
Pacific" BUTTERS has
85
given
descriptions
of
the two
species
in question
but
I do not
think he has found any more exact characters by means of which
the two
species could be separated.
The form of the carpogonial
branches
he
does
not mention
and
a
figure
of
the
cystocarps
would have been very desirable.
This
species
occurs
both
in
sheltered and
in more exposed
places.
It has been found
as an epiphyte upon
Udotea flabellata
but
it
is attached mostly to
stones,
shells
etc.
It occurs in shal-
low water mostly; once
I have taken
it
in a depth
of about 20
meters.
It has been found
at
St. Croix:
Lime
Tree
Bay, Rust up Twist;
St. Jan:
off Cruz Bay.
Geogr. Distrib.: West
Indies, Gulf of Mexico.
Fam.
2. Chcetangiacece.
Subfam.
1. Scinaieae.
Scinaia Bivona.
1.
Scinaia complanata
(F. S. Collins) Cotton.
COTTON, A. D., New
or little-known marine Algae from the East (Kew
Bulletin,
1907,
p. 260) ex parte.
SETCHELL. W. A., The Scinaia Assemblage
(University of
California Publications,
vol.
6, no. 5, 1914, p. 100).
Scinaia furcellata var. complanata
Collins,
in Phyc. Bor. Am.,
Fasc. 17,
no. 836, 1901; Rhodora,
vol. 8,
p. 110,
1906.
Scinaia furcellata Harvey, Nereis Bor. Am., part 2, p. 136 (ex parte).
var. intermedia
n. var.
A var. typica
pra3cipue
differt
fronde
angustiore
cylindrica,
axi
centrali
conspicua.
In several respects the specimens found show very essential dif-
ferences from SETCHELL'S description,
1. c., that
I have no hesitation
in considering them as representing a new variety.
The
specimens
(Fig. 93)
reach
a
length
of
8 cm.
They
all
have a narrow frond the diameter of which reaches about 1
2 mm
only, resembling as to
this character the narrow specimens men-
tioned by SETCHELL.
As to the question whether these narrow specimens
are
flat-
tened
or not SETCHELL was not
successful
in solving the question
with
certainty
only having
dried
material
at
his
disposal.
He
writes: "While
it
is
difficult to be absolutely certain whether the
narrow forms are
flattened
or not, they seem to be so."
I have
86
several
specimens
preserved
in
alcohol; when
these
are
put
in
water they soon become turgescent and seem to assume quite the
habit of the living plant.
These specimens have shown themselves
quite terete (Fig.
93).
As
far as
I remember the living specimens
were
also
terete.
Normally the thallus
is not constricted but
in the lowermost
older part of the plant narrowings
are found rather often.
These
are, however, scarcely quite normal,
it seems rather as
if they ori-
ginated
from
some
kind
of
damage,
parts
of
the
thallus
having been cut
off and young
thin
filaments
having
grown up from the
older and broader
ones and
in
this way giving rise to the
constrictions.
As
to
the
axial
strand
this was
quite
distinct through the whole
thal-
lus in the specimens preserved in spirit
(Fig. 93),
with
the
exception
of
the
lowermost
part
quite
near
the
base
where the
tissue
of the plant
is more
compact
and
less
translucent;
in
the
dried specimens on the other hand
it
was not
visible.
It
consists
of about
20
30 broader filaments with propor-
tionally tkick
walls.
The shape
of
the
epidermal
cells
(compare Fig. 94) seems to agree exactly
with
the
description
of
SETCHELL;
they
are
flattened
or
a
little convex
at
the
upper
(outer)
end,
closely
packed,
3
Ggonal
in
surface
view,
in
section quadratic
to
flattened rect-
angular, about
22
38 /j. broad and 2430^
high.
Below the epidermal
cells the cells with chromatophores form
together a very loose
cell-layer most of the
cells being quite
free
with large open intervals between them. To judge from SETCHELL'S
description
and
figures
the
cells
in my
plant seem
to be more
elongated pyriform than those
in
his plant (compare
Fig. 94 a).
The shape and the arrangement
of the cystocarps appears to
be
in
good
accordance
with
the
description
of
SETCHELL;
the
cystocarps
occur
scattered
over
the whole
surface
of
the
frond
(Fig. 93) and are globular to pyriform
in shape, narrowed abruptly
Fig.
93.
Scinaia
complanata
(Collins) Cotton, var. interme-
dia nov. var.
Part of a plant
with cystocarps. (About 2:1).
87
outwards, about 200 // long and 170 // broad, but both
larger and
smaller ones
occur.
In
a
young
growing
tip
SETCHELL
found
the
"punctnm
vegetationis" convex
projecting.
As
to
this
SETCHELL
remarks:
"Whether
this
is
normal
or
not,
it
is
strikingly
different
from
the depressed punctum
vegetationis as observed
in
all other species
of
Scinaia
examined."
In my
specimens
this
is not
the
case;
the
tips
of
the plants
in a turgescent
state
certainly appear to
be convex projecting but when somewhat magnified the growing
region
is
clearly found
to be sunk.
It
can
not
be
denied
that
these
differences
in my
plants
from the typical Scinaia complanata are very essential.
Even
if
I
left
out
of
consideration
the
fact
that
in SETCHELL'S
plant the
growing point is not sunk,
which
as pointed out by
SETCHELL himself,
is very
probably not normal, the
terete
thallus
in
my
plant
is
a
very
strik-
ing
character.
And
the
axial
strand
being
di-
stinct through
the whole
thallus
is
of
course
also
Fig. 94. Scinaia complanata (Collins) Cotton.
var. intermedia nov. var.
a, part of the epi-
dermal
cell-layer seen from the inner
side
showing the arrangement of the assimilating
cells,
c, transverse section of the same
tis-
sue,
b, epidermal cells and antheridia seen
from above,
(a and b about 250
: 1, c about
150:1).
important
and
to
these
characters
may
yet
be
added the narrow thallus.
On account
of
these
differences
we
apear
to
be
entitled
to
consider
these
narrow
forms
as a variety to which
I propose the name
intermedia,
this
variety appearing to me
to be a connecting link between Scinaia
complanata and Scinaia
fnrcellata.
In
his
newly
published
highly
interesting
paper
on
Sci-
jiaia
furcellata,
SvEDELius 1
)
describes
for
the
first time
mono-
spores
as occurring
in
this
species.
As
is well known tetraspores
are
never met with
in Scinaia and
the discovery of
the mono-
spores
is therefore highly interesting.
I have been looking care-
fully
for
these
organs
in my
specimens
but
without
success,
only antheridia were
present.
Also
I
did
not succeed
in finding
SVEDELIUS, NILS, Zytologisch-entwicklungsgeschichtliche
Studien iiber
Scinaia
furcellata.
Ein
-Beitrag
zur Frage
der
Reduktionsteilung der
nicht tetrasporenbildenden Florideen.
(Nova Acta Regiae Soc. Sclent.
Upsaliensis,
Ser. IV, Vol.
4, No.
4.
1915).
88
hairs.
The
presence
of
hairs
in Scinaia
furcellata
is mentioned
by RosENViNGe 1
). These are now described in detail by SVEDELIUS.
This
plant
has
been
found
in
deep water only,
in
dephts
from
20
30 meters.
The specimens were collected
in the month
of March and had antheridia and
cystocarps.
It has been gathered in the sound between St. Thomas and St. Jan
in several places
off Cruz Bay, and off America
Hill
in the sea to the north
of St. Jan.
Geogr. Distrib.
Florida, Bermuda.
Subfam. 2. Chaetangieae.
Galaxaura Lamouroux.
In
his
very
valuable
monographical
work, "Om
Floride-
slagtet
Galaxaura,
cless
organografi
och
systematik"
(Kongl.
Svenska Vetensk.-Akad.
Handl., Bd.
33, No.
1,
Stockhlom
1900)
KJELLMAN has shown that most of the older species are collective-
species,
in
reality comprising
often
several
easily distinguishable
species.
As a
result
of
his examination KJELLMAN
describes a great
number
of new
species,
he
mentions
in
all
62, many
of which
seem
to be very nearly
related.
As
regards these
species, how-
ever,
in
all
cases
with
which
I am personally acquainted
they
seem to be well founded.
These
many
species
are
relegated
by
KJELLMAN
to
nine
principal
groups,
based
essentially
upon
the
different
develop-
ment
of the
assimilating
tissue.
KJELLMAN
based
his work exclusively upon
material which
was
found
in
his own
herbarium,
and
in
Herb. ARESCHOUG
in
Stockholm
supplemented
with
specimens
from
J. AGARDH
in
Lund.
Without doubt
this material has proved to be very
rich
as
is evident from the numerous
species
it contained, but, never-
theless,
KJELLMAN'S work would
have
been
yet
more
valuable
had he
also cleared up,
as
far
as
possible,
the older species and
identified
them
with
the
forms
which
were
found
in
the
col-
lections examined by him.
This ought
especially to be done with
the
species
of ELLIS
and
SOLAXDER
described
in "The
natural
history
of many
curious
and
uncommon
Zoophytes", London
1786,
a most valuable work
for that time.
ROSENVINGE,
L. KOLDERUP, Remarks on the hyaline unicellular hairs
of
the
Florideae.
(Biologiske Arbejder
tilegnede EUG. WARMING paa
hans
70 Aars Fodselsdag.
Kobenhavn
1911,
p. 204).
89
It
seems, however, most
probable
that these old
plants are
no longer in existence.
At my request Mr. A. D. COTTOX has most
kindly made a search
in the Kew Herbarium without success and
furthermore
he
writes
to me
that
Mr. A. GEPP
tells him
that
none
of ELLIS and SOLANDER'S types
are
in
the
British Museum
and
that
he together with
Mrs. GEPP
had
been
to
the
Royal
College of Surgeons, where the
collection
of ELLIS and SOLANDER
was supposed
to have been preserved and had made a personal
search also without
success.
But
of course this negative result
is
also
of interest; had the
species
of ELLIS and SOLANDER existed
an examination
of these would
certainly have resulted in
several
of the
specific names
of KJELLMAN being changed.
By the
fact that LIEBMAN and 0RSTED have sent ARESCHOUG
material
of many
of the
algae which they have
collected
in the
West
Indies,
KJELLMAN
has
had
relatively
rich
material from
this region and
several
of
his
species
are based upon specimens
from the Danish
Islands.
During the determination
of my
col-
lection
it has been
of great help to me to have had on loan all
the material
of Galaxaura determined by KJELLMAX.
In the following survey
11
species
are mentioned
belonging
to the following 5
of KJELLMAN'S
9 groups, namely:
Sectio
I. Rhodura
Kjellm.
A. with long assimilating filaments
.
.
.
.
1.
G. comans
Kjellm.
B. with long and
short assimilating filaments.
I.
assimilating filaments often clearly arranged
in belts
2.
G. subrerticillata
Kjellm.
II.
assimilating
filaments
evenly
distributed
over
the
whole
surface.
a.
thallus with long internodes,
flagellate
3.
G. flagelliformis Kjellm.
b.
thallus with shorter internodes
1.
large, much ramified tufts, thallus flexible, densely
covered with long hairs
.
4.
G. lapidescens (Sol.) Lamx.
2. low tufts, thallus fragile, rugose.
5.
G. delabida Kjellm.
Sectio
II.
Microthoe Dcsne,
J. Ag.
a.
thallus
quite
or
nearly glabrous, annularly constricted
internodes
of nearly the same length
6.
G. rugosa (Solander) Lamx.
b.
the assimilating filaments more persistent, less annularly
constricted internodes of variable length.
7. G. squalida Kjellm.
90
Sectio
III.
Euyalavcaura (Dcsne)
Kjellm.
a.
With
broader,
proportionally
shorter
and
somewhat
rugose internodes
8.
G. fragilis Lamk.
b. With long, nearly cylindric internodes
9.
G. cylindrica Solander.
Sectio
IV.
Bracliycladia Sonder.
10.
G. marginata
(Sol.) Lamx.
Sectio V.
Vepreculce
Kjellm.
11.
G. occidentalis
n. sp.
Sectio
I.
Rhodtira
Kjellm.
1.
Galaxaura comans
Kjellm.
KJELLMAN,
F. R.,
Floride-slagtet Galaxaura,
p. 44.
This
species KJELLMAN based upon a small,
rather tiny but
otherwise well developed
specimen
collected
at Guadeloupe
and
sent to ARESCHOUG from CROUAN.
The specimen (Fig.
95)
I have gathered
is large and vigorous,
much
larger
than
the
original
one, reaching a
height
of
about
12 cm.
It
is irregularly ramified with long internodes
of very vari-
able
length
up
to
3 cm
or even
more.
The branches
are very
rigid and protuberant
; their diameter, including the
hairs, reaches
3
5 mm being narrowed towards the apex.
The whole thallus
is densely covered with
rigid
prominent
hairs and
is
of a dark
red
colour.
A transverse section
shows
that the
medullary
tissue
con-
sists
of
proportionately
thick
filaments
commonly
about
20
/j.
thick, but both thinner and thicker ones are
present.
The
peri-
pheral
cells which bear the
assimilating hairs
are mostly almost
isodiametric
often
quadrangular
about
50
fj.
broad
(Fig.
96 a);
each
cell commonly bearing a single assimilating filament, seldom
two
(Fig. 96 a).
The
assimilating filaments
consist
at
their base
of a large oval
cell about 80 /* long and 50 // broad
; then
follow
two
or
three
still
oval
cells
decreasing gradually
in
size.
The
rest of the filaments consists of cylindrical cells about 19 // broad
;
the length
of the
cells
is rather variable, some
are up 40 // long
or more, others especially in the upper end
are shorter, not much
longer than they are broad. The whole filament reaches a length
of up to
1
2 mm.
91
KJELLMAN
found
ramified filaments rather frequently in
his
specimen and
these occurred
also
in mine
(Fig. 96 b).
f-tggl
Fig. 95.
Galaxawa comans
Kjellm.
Part
of a plant.
(About
l,r,
: 1).
This species has only been found once in a depth of 8 fathoms in the
sea
to the north
of St. Jan:
oft America
Hill.
Geogr.
Distrib. West
Indies.
92
2.
Galaxaura
subvcrticillata
Kjellm.
KJELLMAN,
F. R.,
Flo-ride-slagtet Galaxaura,
p. 48.
This species has
been described
from
specimens
which
0RSTED
col-
lected
at St. Croix and
sent to ARE-
SCHOUG.
In
the Botanical Museum,
Copenhagen,
some
more
specimens
of
0RSTED's
from
St. Croix
are
to
be found which quite agree with the
specimens determined by KJELLMAN.
The specimens
I have
collected
(compare Fig. 97) seem to agree very
well with the
original examples.
In
this species both long and short assi-
milating
filaments
are
present
and
the
most
striking
character
is
the
verticillate
arrangement
of
the
fila-
ments.
This annular arrangement
is
most
clearly
present
in
the young
parts
of
the
thallus,
in
the
older
ones the long hairs occur in a more
scattered manner over the whole sur-
face
and
some
specimens
are
even
found
in which the annular arrange-
ment
is much
reduced, the
specimens
having an almost even but rather open
covering
of
hairs
over
the whole
sur-
face.
KJELLMAN
explains
this
fact by
considering that the short hairs later on
grow out
more
or
less
into long ones.
The
surface
of
the
thallus,
espe-
cially
in that
of the upper young ends,
is
rugose and
often
clearly annulated.
The
internodes
are
nearly
cylin-
drical, mostly constricted
at the
base,
of
variable
length
but
usually
short
seldom exceeding
1 cm.
The
colour
of my
specimens was
greyish olive-green with a reddish tinge especially
in the younger
parts
of the
thallus.
A transverse section shows the medullary tissue to
consist
of
the usual, rather thick walled, cylindric cells woven together.
The
Fig.
96.
Galaxaura
comans
Kjellm.
a, basal parts of
as-
similating filaments with the
supporting
cell,
b,
base
of
a ramified
filament.
(About
150:1).
Fig. 97.
Galaxaura subver-
ticillatal\]Q\\m.
Part of the
thallus.
(About
1,5
: 1).
93
diameter
of the central tissue being about 600 //.
The cells which
bear the
assimilating
filaments
are well developed, quadrangular
(sometimes
triangular), about 45 p
broad.
The short assimilating filaments usually consist of three some-
times
of two
cells
only. The basal
cell
is
large, oval, about
65 p.
long and 45 // broad.
The diameter of the uppermost small
cells
varies between 16 and
25 //.
The
sizes KJELLMAN gives
for these
cells are somewhat greater
but
in the specimen of the
original
material
which
I
have examined
I found the
size of these
cells agreeing
very well with that of mine.
In the long assimilating fila-
ments
the
basal
cells
are
of a
similar
size to
those
of the short
filaments, the
filament itself is about 16 /^
thick
and
consists
of
cy-
lindric
thick-walled
cells
about 30 //
long.
This
species
was
found
growing
in shallow water and
in an exposed locality at Long
Reaf
near
Christiansted,
St.
Croix.
Furthermore
a speci-
men washed
ashore at Sandy
Point,
St.
Croix,
has
been
sent
to me
by
Dr. HAMBUR-
GER.
ORSTED
does
not
indi-
cate the locality where he found
his specimens.
Mile.
VICKERS
mentions
this
species from Barbados
in
her
list and
I have specimens of
it from Jamaica (Kingston) where
it was
found by Mr. O. HANSEN GANNESKOV.
Geogr. Distrib. West
Indies.
Fig. 98.
Galaxaura
flagelliformis
Kjellm.
Tranverse
section of a young thallus with
mostly long assimilating filaments in diffe-
rent stages of development. (About 150:1).
3.
Galaxaura
flagelliformis Kjellm.
KJELLMAN,
F. R., Om Floride-slagtet Galaxaura,
p. 47.
This
species was
based by KJELLMAN
upon specimens
from
Key West,
Florida,
collected by BAILEY and preserved
in
Herb.
ARESCHOUG
in Stockholm.
94
My
specimens
seem
to
agree
quite
well
with
those
of
KJELLMAN.
In a transverse section
of the thallus
(Fig. 98)
it is seen that
the
medullary
layer consists
of
rather
thin
filaments
woven
between
each
other;
they
are
of
variable
breath,
their diameter
being
12
16
fj. thick
or even more.
The supporting
cells
at
the
periphery are
mostly not much
developed;
they
are
irregularly
3
4-gonal
(Figs. 99
and
100),
up
to
40 //
in
diameter.
They carry each a
single
or more rarely two
assimilating filaments, short or long. The short
ones
(Fig.
99 b,
Fig. 100)
mostly
consist
of
three
cells, someones
only
of two; the
basal
cells are
large, oval, about
60
70 // long and
40
{JL broad, the others smaller, the uppermost
have
only
a diameter
about
27 p
long.
The
basal
cells
in
the
long assimilating filaments
(Fig.
99 a)
have
nearly
the
same
size
and
shape.
The breadth
of the
cells
in the
cylin-
drical
part
of
the
filaments
seem
to
vary
somewhat,
in one specimen
I found
the
dia-
meter to be about 16^,
in another even 18 p.;
KJELLMAN
states the diameter to be 15 //. The
length
of
the
cells
is
often
more
than
double
the
breadth.
Regarding
the
habit
of
the
plant
the
accompanying
figure
(Fig. 101)
gives an
idea.
The
plant
is,
as
pointed out by
KJELLMAN,
large,
about 16 cm
high
not much
ramified
with
very
long
internodes and
the branches
spreading much and often somewhat recurved
at
the
summits.
It
is
evenly
covered
with
hairs over the whole surface and
of a reddish
brown
colour.
This
species
has
been
found
in
deep
water only clown to a depth
of about 20
30
meters.
Fig. 99. Galaxaura
flagelliformis. a, ba-
sal part of long as-
similating hair,
b,
short
assimilating
filaments, one with
two
cells,
another
with three. (About
150:1).
St.
Jan:
Off
Hermitage
and
in
several
pla-
ces
in
the sound
between
this island and St. Tho-
mas.
Geogr. Distrib.
Florida, West
Indies.
Fig.
100.
Galax-
aura
flagelliformis
Kjellm. Short assi-
milating
filament
with
chromatp-
phore and pyrenoid
in
the upper
end
of the cell.
(About
175:
1).
95
4.
Galaxaura lapidescens
(Sol.) Lamx.
LAMOUROUX,
J.'V. F.,
Histoire des
Polypiers
corall.
flexibl.
1816,
p.
264.
KJELLMAN,
F. R.,
Floride-Sliigtet Galaxaura,
p. 3943.
Corallina lapidescens Solander in ELLIS and SOLANDER, Natural History
Fig. 101.
Galaxaura
flagelliformis
Kjellm.
Part
of a
plant.
(About
1,5:1).
of many curious and uncommon Zoophytes, London 1786,
(ex p., comp. the
text below).
As pointed out by KJELLMAN so many different forms occurring
in
nearly
all
tropical
seas
have
in
the
past
been
referred
to
Galaxaura
lapidescens,
originally described by SOLANDER, that
it
was
to be supposed,
a
priori, that
this
species comprehended
in
96
reality several
distinct
species,
all
densely
haired
forms
having
been
referred
to
it.
Referring to the comprehensive survey of KJELLMAN, quoted
above,
for further
details
of
this question
I only wish
to
point
out
here
that SOLANDER
already
mentions
two
varieties
of
his
Corallina
lapidescens.
He says
(1.
c., p. 113)
: "There
are two va-
rieties
of
this Coralline, one that
is always dichotomous, Tab. 22,
fig.
9, and another that sends out three or more joints from the
same
place, Tab. 21,
fig. g," and
his
description
of some
speci-
mens "preserved
in
spirits
as
they were
taken
out
of the sea"
in which the "fine short reddish
hairs come out
in regular whirls
or
circles", seems to suggest that he has had to do with a third
species
e.
g. G. subverticillata
or
a
similar one.
While SOLANDER
nearly
always mentions
the
localities
from whence
the
plants
originate, he
unfortunately
does
not give any
localities
for this
species.
As
is
clear
from
this
the
founder
of
the
species
referred
perhaps even
three
different
forms
to
it and
afterwards
nearly
all
long-haired
forms
have,
as
pointed
out
above,
been
con-
sidered
as
belonging
to
it.
The
only
investigator
who
has
tried
to
divide
this
species
is
KUTZING who
in
"Tabulae
Phy-
colgicse",
vol. VIII,
p. 38 has two
species
namely: G. lapidescens
and
G.
tomentosa.
But
J. AGARDH
in
Epicrisis,
p.
530,
refers
KUTZING'S
species tomentosa
to
G. lapidescens
as
a
variety
only
That
J. AGARDH nevertheless had some doubt how
far G. lapides-
cens should be separated
is evident,
as was
also pointed out by
KJELLMAN, not only from his remark
in
Epicrisis,
1.
c.
: "an plures
species
hoc
loco
lateant", but
also
from what
is
said
in
"Till
Algernes Systematik", 4de
afdeling, VII
Floridese,
p.
75.
Yet
I
shall
only
mention
that ASKENASY
in "Forschungsreise
S. M. S.
Gazelle", IV Teil, p. 33 with regard to the occurrence
of G. lapi-
descens says that
it
is common
in
all tropical
seas. Thus matters
stood when KJELLMAN commenced
his thorough
investigations.
As
a
result
of these studies
this
species
is now divided
into
a
great
number
of
species
with
more
restricted
distribution.
But
as KJELLMAN
had
no
opportunity to examine the
original
specimens
of
ELLIS
and
SOLANDER
he
did
not
know
with
certainty
which
of
his
species
ought
in
future
to
be named
lapidescens
and
among
the
species
which
he
refers
to
the
group
Rhodura
he
does
not mention
it.
On the other hand in
the
introductory
remarks
to the Rhodura
group
he
points
out
that
in
his opinion
this
species ought to be maintained and
he
97
adds
that
he
thinks
that
the
plant which
KUTZLXG
in Tabulse
Phycologicse,
vol.
8,
pi.
38,
fig.
I
has
figured
as
G.
lapidescens
might correctly be considered
as
this
species.
However,
it seems
to me, the
figure
(pi.
21,
fig. g)
of
ELLIS and SOLANDER
gives a
very good
idea of
the
plant and
I think
it
is more correct
to
take
this
the
first
published
figure
of
the
plant,
as
the
type
of
the
species.
In
spite
of
this
I
do not mean that the
figure
of
KUTZING
in
question
would
not
also
represent
a
form
of
this
species
1
).
An
examination
of
the
original
material
of
ELLIS and SOLANDER would of course be the most conclusive but
as mentioned
in my introductory remarks to this genus the type
specimens
do
not now
seem to
exist.
All the specimens
I
have found are much ra-
mified, forming large d en-
se tufts (Fig. 102). These
are fastened to the sub-
stratum by means
of a
broad
disc
from
which
several
branches
often
arise. These branches are
repeatedly
subdichoto-
mously
ramified.
The
internodes
are cylindric
Fig. 102.
Galaxaura lapidescens
(Sol.) Lamx.
of variable length, some-
Part of a Plant -
< About ^
: li-
t/lines they are more than
1 cm long sometimes
shorter.
In
the
middle
of the
thallus the
diameter of
the
branches without hairs reach a
length
of about
J
) As
on
account
of
this
fact
it
seemed
to
be
of
great
importance
to
examine
the
two
plants
upon which
KUTZING
based
his
draw-
ings
of
Galaxaura
lapidescens and Galaxaura tomentosa
I
asked Mm
WEBER
to
allow me
to
investigate a
little
bit
of
the two
plants
in
question
which
as
said
by
KUTZING
both
originate
from
Mexico.
At my
request
she
greatly
obliged me
by
sending
a
small
piece,
enough for microscopical examination, of Galaxaura tomentosa originat-
ing from Mexico, but she told me at the same time that in the Herb.
KUTZING belonging to
her
there was
no
specimen
of Galaxaura
lapi-
descens from Mexico.
Having examined the piece of Galaxaura tomen-
tosa
I
arrived
at
the
conclusion
that
this
plant
of KUTZING
is
like
Galaxaura Liebmanni (Aresch.)
Kjellm.,
described
as Holonema
Lieb-
manni
4
years
earlier
by
ARESCUOUG
in
"Phycese
novae",
1854,
p. 356.
7
98
1 mm, with the hairs the diameter
is more than 2 mm. The hairs
are evenly
distributed
over
the
whole
thallus giving
it
a
felted
appearance.
The colour
is rather variable,
in some specimens red-
brown in others greyish olive-green with a more or less reddish tinge.
As to the anatomical structure
the
medullary
tissue
consists
of
rather thick-walled filaments woven
together. The filaments are of very
variable
size
most
often
about
11
13 //
broad
but
some
occur
which reach more than the double
thickness;
the
diameter
of
the
whole
tissue
reaches
a
width
of
about 650
<JL.
Towards
the
periphery
these
filaments bare the polygonal
sup-
porting
cells commonly
found
in
this
group
(compare
Fig.
103).
These are mostly 4-gonal and about
40
50
[i. broad.
The
assimilating
filaments
arising
from
these
cells
are of two different kinds, some short
and others long.
In the older parts
of the thallus the long assimilating
filaments especially occur while the
shorter ones usually are very
rare,
in
the young
thallus
the
shorter
assimilating filaments
are
quite
as
common
as the
longer
ones.
The
short
filaments
consist
of
three,
sometimes only
of
tw
ro
cells
(Fig.
103 b) and these
cells decrease
ra-
pidly
in
size upwards.
The low
rest
cells
are large up
to 70
fj.
or even
longer and about 45
jj. broad, the
uppermost ones
are only about 28
30 // broad.
The basal cells in the long assimilating filaments are of about
the same shape and
size as those
in the
short filaments.
Above
the low
rest
largest
one, a smaller oval
cell
follows and sometimes
the
following
cell
is yet somewhat swollen
in
the
middle while
the
rest
of the cells
in the filament
are cylindrical, mostly about
Fig.
103.
Galaxaura lapidescens
(Sol.) Lamx.
a, long assimilating
filaments,
b,
short
assimilating
filament and basal part of a long
one
issued from
the same sup-
porting
cell.
(About 150
: 1).
99
19 n
thick
reaching
a
length
of
up
to
2
3
times
their own
breadth.
All walls
in
the
filaments
are thick and
stratified not only
in the
basal
cells but also in the cylindrical upper ones (Fig. 104).
In
the
cells
of
the
assimilating
filaments
a
well-developed
chromatophore is present (Fig. 104).
It
lies near the upper end of
the cell,
is campanulate with long prolongations down the wall of
the
cell
and
contains
a
large
pyrenoid
in
its
centre.
In
the
cylindrical
cells
the
pyrenoid
lies
nearer
the
middle
of
the
cell.
Of the
species described by KJELL-
MAN
this
plant
seems
to
come
near
to
Galaxanra
Liebmanni.
Besides
the
small
type
specimen
in
Herb.
AKE-
SCHOUG
I
have
seen
some
larger
ones
also
collected
by LIEBMANN
in
Mexico
and
belonging
to
the
Botanical
Mu-
seum,
Copenhagen.
These
show
that
the
species
has
a
more
robust
and
thicker
thallus,
the
filaments
in
the
medullary tissue
are thicker about 19 //,
there
are often
2
3
large
cells
at
the
base
of
the
long
assimilating
filaments
and
the
basal
cell
of
these
are
some-
what
larger
(about
75 // long and
55 n
broad);
also the
cylindrical
part
of
the
long assimilating filaments
is thicker,
its
diameter reaching 22 p.
Also
G.
ramulosa
seems
to
show
some
likeness
to
this
species,
but
it
differs among other things by the
vigo-
gorous short assimilating filaments the uppermost
cells
of which
are
relatively
large, and
by
the
thinner,
long assimilating
fila-
ments.
G. lapidescens was found
mostly in
sheltered
places
and
in
shallow water,
e.
g.
in lagoons and
bays,
once
it was
taken
in
the open sea
at a depth
of about
12 meters.
St. Croix:
The
harbour
of
Christianssted,
off
Frederikssted,
Lime
Tree Bay.
St. Thomas: Bovoni Lagoon.
Fig
104.
Galaxaura
la-
pidescens
(Sol.)
Lamx.
Basal part of an
assimi-
lating filament with chro-
matophores
and
pyre-
noids; below in the
cells
the nuclei are made visi-
ble by staining.
(About 400:1).
Geogr. Distrib.
: West
Indies.
7*
100
5.
Galaxaura delabida
Kjellm.
KJELLMAN,
F. R., Om
Floride-slagtet Galaxaura,
p. 49.
Of
this
plant
I have only seen the
original material which
is now
kept
in
Herb. KJELLMAN
in
the Botanical Museum
in
Upsala;
it was
collected
at
St. Thomas and
distributed by
P. T.
CLEVE.
The original material consists of numerous mostly small pieces.
KJELLMAN points out that the most characteristic feature of this
species is that the filaments in the medullary tissue differ very much
in thickness, and that the supporting cells are often not developed,
the assimilating filaments
in
this case growing directly out from
the
medullary
filaments.
The
short
assimilating filaments often
consist
of
two
cells
only.
The long assimilating
filaments
are
about
15 p
broad
and
have comparatively short cells, 1Y2
2
times
as long as broad.
KJELLMAN supposes that the plant
forms
lo\v
tufts
pressed
to
the sub-
stratum.
Geogr.
Distrib.
:
At
present
only
known from
St. Thomas.
Fig. 105.
Galaxaura rugosa
(Solander)
Lamx.
Part
of
a plant.
(About l/2
: 1).
Sectio
II.
MicrotJioe Dcsne,
J. Ag.
6.
Galaxaura rugosa (Solander) Lamx.
LAMOUROUX,
J. V.,
Histoire des
Poly-
piers coralligenes
flexibles,
Caen 1816,
p. 263. KUTZING,
Fr., Tabulae Phy-
cologicse,
vol. VIII,
tab. 33,
fig.
1.
AGARDH, J. G.,
Epicrisis,
p. 528.
KJELL-
MANN,
F. R.,
Floride-slagtet Galaxaura,
p. 55.
Corallina rugosa Solander in ELLIS, J., and D. SOLANDER, The Natural
History
of many curious and uncommon
Zoophytes, London
1786,
p. 115,
tab. 22,
fig. 3.
KJELLMAN
does
not
give any description
or
figures
of
this
old
species of SOLANDER but refers to the description of
J. AGARDH
in
Epicrisis
and
to
the
figures
of
ELLIS and
SOLANDER,
p. 115,
tab. 22,
fig.
3, and
of KUTZING
in Tabulae
Phycologicae, vol. VIII,
tab. 33,
fig.
1.
But on the
other
hand, when describing several
new
7 species related to
or formerly considered
as forms
of G. ru-
gosa, he points out
in what way they
differ from
this
species.
The specimens which
I
refer to
G. rugosa
(Fig. 105)
are
cer-
tainly very
like those
I refer to the following species, on the other
101
Fig.
106.
Galaxaura
rugosa
(Solander)
Lamx.
Transverse
section
of the thallus and sur-
face
cells seen from above.
In
the
cells
the
campanulate
stellate
chrpmatophores
with
the
pyrenoid
in
the
middle.
(About 250:1).
hand they show just the differences
KJELLMAN has noted.
The most essential and striking
difference is the smaller development
of the
assimilating
filaments.
The
well
developed
annular
groups
of
hairs
found
in
G.
squalida
in
the
younger
parts
of
the
thallus were
not present in these specimens
; only
in the older part of the thallus hairs
occasionally occurred. The diameter
of these
hairs was about
16
18^.
The
ramification
is
perhaps
somewhat
more
regularly
dichoto-
mous
in
this species, the internodes
being
nearly
of
the
same
length,
but
variations
occur.
Owing
to
the
lesser
development
of the
hairs
the
surface
of
the
plant
is
almost
quite
smooth.
The
annulations
are
well developed.
In the dried
specimens
the
green
colour was
more promi-
nent
and
the red
tinge
originating
from
the
hairs
in
G. squalida was lacking.
As to the anatomical structure
I have not
found any
differences worth
mentioning.
The
fig. 106 shows a transverse section
of the
peri-
feral
tissue;
this consists of
3
4 layers of
cells
the
innermost
largest;
large
lobed
cells
were
common, quite
in accordance with
that which
is found
in
G. squalida.
In a collection from Lime Tree Bay
at St.
Groix hyaline unicellular hairs were found abun-
dantly
in the young tips of the plant (Fig. 107).
These
hairs grow out from the peripheral
cells.
They are long, nearly cylindric, when full grown
about 200
300 // long and 68^
thick.
The
upper end
is
filled with protoplasm.
Their de-
velopment
seems
to
agree
perfectly with
the
description
of
ROSENVINGE
as
to similar
hairs
in other Florideaa 1
).
Fig. 107. Galaxaura
rugosa
(Solander)
Lamx. Surface cell
with
long
unicel-
lular hair.
(About
175:1).
ROSENVINGE, L. KOLDERUP, Remarks on the hyaline
unicellular hairs of the Florideae in BiologiskeArbejder
tilegnede EUG. WARMING, Kobenhavn, 1911, p. 207.
102
This
species grows
in
shallow water and
in somewhat
shel-
tered
places.
It seems
to be common.
It has been
collected
in the following places.
St. Croix:
Coakley Bay,
Christianssteds Har-
bour,
Rust
up
Twist,
Cane
Garden,
Sandy
Point, Lime
Tree
Bay.
Some
old
specimens
from
St. Thomas,
collected
by
RAVN,
are
found
in the
collections
of
the
Botanical Mu-
seum, Copenhagen.
Geogr. Distrib.
: West
Indies.
Fig. 108.
Galaxaura squalida Kjellm.
Part of the thai! us showing the groups
of hairs occurring now and then espe-
cially in the young parts of the thal-
lus. '(About
1,5:1).
Fig. 109. Galaxaura squalida Kjellm.
Transverse
section
of
the
thallus
with
lobed
cells
and
assimilating
filaments, one of which
is ramified.
(About 150:1).
7.
Galaxaura
squalida
Kjellm.
KJELLMAN,
F. R., Om
Floride-slagtet Galaxaura,
p. 55.
This species
has been described from specimens
collected
at
St. Croix by ORSTED and preserved
in Herb. ARESCHOUG in Stock-
holm.
In the herbarium
of the Botanical Museum, Copenhagen.
I
have
found
several
of ORSTED'S
specimens
belonging
to
this
species. The
description below
is
especially based upon my own
material.
The plant
(Fig. 108) forms dense
richly ramified
tufts which
are
fixed
to the substratum by means
of a broad
disc composed
103
Fig. 110.
Galaxaura squalida
Kjellm.
Transverse section of the thallus show-
ing
the
periferic
tissue with chroma-
tophores and pyrenoids.
(About 250
: 1).
of numerous irregularly bent filaments
felted together; these fila-
ments have
fairly thick walls and
a breadth
of about 16 ^
while
their length
is
often up
to ten times the breadth.
From
this base
several
branches grow up and
these
are
re-
peatedly
dichotomously
ramified.
The
internodes
are
of
very
variable
length from one
to
two cms.
The
branches
are
cylindrical, also
in the
dried
condition, with the exception
of the quite young upper ends,
not yet much incrusted which
collapse
being more
or
less
flat when
dry.
In the
spirit
material the apices are nearly
cup-shaped with
the sunken
growing point
in the middle.
The colour
of
the
dried
plant
is a sordid yellow-green
with a red-brawn tinge espe-
cially where the
assimilating
hairs
are
present.
These
do
not
occur evenly distributed over
the whole surface; they are
most
numerously
present upon the
younger
parts
of
the branches and
often show here an annular
arrangement but quite scattered ones
also often occur especially
upon
older parts
of the
thallus.
The surface
of the plant
is mostly rather
clearly annulated.
A
transverse
section
shows
that
the
medullary tissue
is composed of rather thick-
walled dichotomously branched filaments con-
sisting
of long cylindrical
cells of which the
diameter varies from 7 to 16 ^.
The periferal
tissue
consists
of
short often dichotomously
ramified
cell-threads composed
of 3
4
cells
(Figs. 109,
110).
Of these the innermost are
the
largest;
they
are
mostly
roundish
but
very large ones, irregularly shaped and lobed
are often found
(Figs. 109, 111).
These lobed
cells
are
also men-
tioned
and
figured
by
KJELLMAN
and
occur
in
several
other
species.
This
cell
layer
is
about
40
ij.
thick, but
the
cells
are
very variable in size the large lobed cells being often much thicker.
These cells are colourless and contain only protoplasm, cell sap etc.
The next cells are smaller (about 25
30 /^ in diameter), nearly
Fig. 111.
Galaxaura
squalida
Kjellm.
A
lobed
cell
from
the
periferic
tissue.
(About 200:1).
104
Fig. 112. Galaxaura fragilis Lamk.
Part of the thallus. (About 1V2
: 1).
spherical and have rather well developed chromatophores.
Finally
we arrive
at the epidermal
cells, the real assimilating ones.
These
are
short,
10
12
ju> long and
20
24^
broad,
in
transverse
sec-
tion
often
triangular, when
seen
from
above
5
7-gonal
and
closely united (comp. those found
in
G.
squalida,
Fig.
106).
They
contain
a
well
developed
cam-
panulate
chromatophore
with
long
branched
prolongations
running
down
along
the
walls
of
the
cells
(Fig. 110);
in
the
middle
of
the
chromatophore a
pyrenoid
is
present.
But
be-
sides
this,
the
real
assimilating
tissue,
the
plant
possesses
the
above
mentioned
assimilating
filaments
(Fig.
109);
these
are
composed of a row of
cells which
are abuot
2
3 times as long as broad
(lat. about 1518 p) and
have thick
walls,
4 p
thick.
They contain a much ramified chro-
matophore.
The chalk incrustation
is richly developed and found through-
out the whole
tissue.
A
specimen
from
the
harbour
of
Christianssted
had
ap-
parently
ripe
cystocarps.
These
are
nearly spherical with an opening above.
The carpospores
are
large,
oval, about
50 // long and 30 p broad.
My
specimens seem
to agree very
well with the description of KJELLMAX
and with
the
original
specimens
from
St.
Croix.
As pointed
out above with
regard
to
G.
rugosa,
this
species
is
nearly
related
to the present one;
for
the differences between them
I
refer to
the comparative
remarks given above.
Galaxaura
squalida
has
been
ga-
thered
both
in
shallow water
in more
sheltered
places
and
in
deeper
water
at
a
depth
of
about
30
meters
and
in
more
open
sea.
It was found
in
the following
localities:
St. Croix: Christianssteds
Harbour,
off
Frederikssted.
At
the
shores
of
this island
it was also
col-
Fig. 113. Galaxaura fragilis
Lamk.
a, epidermal
cells
seen from
above,
b,
fila-
ments from the
dia-
phragms.
(About 250
: 1).
105
lected by ORSTED.
St. Jan.:
Coral Bay,
and
in the
sound between
St.
Thomas and St. Jan near the island
St. James.
Geogr. Distrib.
: West
Indies.
Sectio
III. Euf/alaxaura (Dcsne)
Kjellm.
8.
Galaxaura fragilis (Lamk.)
Kiitz.
KUTZING, Spec., p. 530. KJELLMAN, F. R., Floride-slagtet Galaxaura, p. 60.
Dichotornaria
fragilis Lamk.
LAMARCK,
J.,
Histoire naturelle des ani-
maux sans vertebres,
t. II,
1816,
p. 145.
The
specimens
(Fig. 112)
have
a glabrous, when
dry often
shining
surface. The annulation which
in some of the specimens
determined by KJELLMAN was very prominent was not so distinct
in my
plant.
The
branches
are
fairly
regularly
dichtomously
forked. The internodes are 4
5mm
long,
mostly slender at their
base
growing thicker upwards, more rarely
nearly cylindrical
;
at
their base an
annular
bursting
of
the calcareous
layer
is often
present.
The colour
of
the
dried
plant
is
light yellow
green often
also more
reddish.
The whole plant
is very fragile.
A transverse section reveals the fact
Fig m
Galaxaura
fragilis
that
the
medullary
tissue
is very
(Lamk).
Transverse section
of
loose;
it
consists
of
dichotomously
the thalhls -
< About 25
ramified,
rather
thick -walled
fila-
ments
running between each other; their diameter
is about
8ft
long. The diaphragms
at the joints the presence of which espe-
cially
characterizes
the
Sectio Eugalaxaura
are
formed
in
the
following manner. Numerous
filaments
are crowded
more firmly
together and
furthermore the ends
of these filaments
are much
thickened,
their
diameter
reaching
often
17^
or
more
(Fig.
113 b).
The
peripheral
tissue
(Fig.
114)
is
about
70 //
thick.
It
consists
of short, dichotomously branched
filaments the
cells
of
which form together a parenchymatous
tissue; with the except-
ion
of the epidermal
cells,
all other cells
in this
tissue are
easily
separable
after
decalcification.
The
innermost
cells
are
the
largest; they are roundish in shape and
their diameter reaches a
length
of
about
35 /*.
Towards
the
periphery
the
cells grow
smaller, the epidermal
cells being the smallest
ones.
These are
fairly
strongly
united
and
when
seen
from
above
5
6-gonal
106
(Fig. 113 a),
about
14 //
broad,
while
their length
in transverse
section
is
seen
to be about
8 //
only.
The chromatophore
is
found
in the upper end
of the
cells;
it
has the common
campanulate shape with
a
pyrenoid
in the
middle.
It
is most developed
in the epidermal
cells, but
it
is in
the whole not
especially
large.
KJELLMAX
points out that
judging
from
ELLIS
and
SOLAN-
DER'S figure 4, plate
22,
it
is not impossible that the plant which
here is called Corallina cylindrica is not the species we now call cy-
lindrica but the present one.
In considering this figure, it certainly
can not be
denied, that the length
of the internodes are
in pro-
portion
to their
breadth too
short, and
that
in
this respect the
figure agrees better with G. fragilis.
But to
state this with
cer-
tainty an examination
of the
original specimen
is necessary.
This
species has been found
in a depth
of about
12 meters
in more open
sea.
Only found once at St. Croix:
off Frederikssted.
Geogr. Distrib.: West
Indies, Atlantic coast
of South America.
9.
Galaxaura
cylindriea
(Solander)
Kjellm.
KJELLMAN, F. R., Om
Floride-slagtet Galaxaura,
p.
64.
Corallina cylindrica in ELLIS, J., and D. SOLANDER, The Natural History
of many curious and uncommon
Zoophytes, 1786,
p. 114.
I have not
collected
this plant myself but
in the
Botanical
Museum, Copenhagen,
several
large
specimens
collected
at
St.
Croix by ORSTED
are to
be found.
ORSTED
does not give any
more
definite
information
as
to
where
he gathered
the
plant.
Some of the specimens reach a length
of more than
12 cm; such
a
large
specimen
of 0RSTED
determined
by
KJELLMAN
is
also
found
in Herb. ARESCHOUG
in Stockholm.
Regarding
an
eventual
change
of name
I
refer to what
is
said about Galaxaura
fragilis.
Geogr. Distrib.: West
Indies, Atlantic coast of South America.
Sectio
IV. BracJiycladia Sonder,
Kjellman,
1.
c. p. 67.
10.
Galaxaura marginata (Solander) Lamx.
LAMOUROUX, J. V.,
Hist. Polypiers
corall. flexibl.,
1816,
p. 264.
KJELL-
MAN,
Floride-slagtet Galaxaura,
p. 77.
Corallina marginata Solander
in ELLIS and SOLANDER, Nat. Hist. Zoo-
phytes,
p. 115,
tab. 22,
fig. 6.
107
Fig. 115. Galaxaura marginata (Solan-
der).
Part of a plant
(About 1,5
: 1).
Zanardinia marginata
J. Ag., Spec. Alg., vol. Ill,
p. 534.
Brachydadia marginata Schmitz,
System.
Ubersicht d. bisher bekannt.
Gatt. der Florideen
(Flora,
47, 1889,
p. 438).
This
species was
founded
upon
a specimen
collected
at
the Bahama
Islands.
The de-
scription
of
KJELLMAN on the
other
hand
is
based
upon a
specimen
in ARESCHOUG'S Her-
barium
in
Stockholm and
on
which he remarks that
it was
collected
at the coast of South
America
at
Bahia (?).
But
among
the
material
of
Ga-
laxaura
in
Herb. ARESCHOUG
which
I have
seen, no such a
specimen is present
; on the other
hand one
is found collected
by LIEBMAN at Havana and
determined
by
KJELLMAN
as
G. marginata. Most prob-
ably this
is the specimen he
refers
to.
KJELLMAN
points
out
that the specimens examined
by him agree well with the
figure
of SOLANDER, and
as
both plants
also
have been
collected
in nearly the same
area he considers himself en-
titled
to
refer ARESCHOUG'S
specimens
to
SOLANDER'S
species.
The
rather
numerous
specimens (Fig 115)
I
have
collected seem
in
all essen-
tials
to agree with
the de-
scription of KJELLMAN. They
differ
from
it
in
one
respect,
however,
the
assimilating
peri-
pheral
cells ending commonly,
but
not
always,
in
a short
api-
culus (Fig. 116),
in a
similar way to that described by KJELLMAN
for
his
species, Galaxaura apiculata from Japan.
This short
api-
Fig. 116.
Galaxaura marginata
(Sol.).
Transverse section of the periferic tissue of
a form with apiculated assimilating cells.
(About 250
: 1).
108
culus
is
not always
present and
in
one specimen
of mine (Nr.
1317) the mucronated
assimilating cells were
rare, nearly
all had
a broadly rounded summit
(Fig. 117).
The specimens
I have collected formed rather large and dense
tufts composed of numerous richly ramified branches.
At the base
the main branches
are
terete or nearly so but higher up
all the
branches
become
quite
flattened.
They
are
either
repeatedly
forked
or irregularly ramified
(Fig. 115).
The colour
of the dried plant
is greyish to olive-green with
a reddish tinge especially
in the upper
parts.
The surface
is dull
and when
seen under a
lens
finely dotted,
this
appearance
ori-
ginating
from
the
closely placed
but
free assimilating cells.
In
this respect
it differs from the Galaxaura
occidentalis, mentioned below, this having
a more even and often shiny surface while
both
plants
otherwise
show
a
striking
remblance in their habit and where grow-
ing together.
In the dried specimens the edges
of
the
branches
are
often
somewhat
pro-
minent
giving
the branches a chanelled
appearance.
In my specimens the transverse stri-
ations were
not much
developed
some-
times
not
at
all;
when
present
they
were
mostly found
towards the summit
of the branches
(Fig. 115).
With
regard
to
the
flattening
of
the
branches
some
differences
are present
in the various
speci-
mens.
In some (my
collection
nr. 1317 a) a
transverse
section
of
the
thallus
is
nearly
oval,
while
in
others
(nr.
1657 b)
this
was
oblong
linear
with
quite
parallel
sides.
In specimens
pre-
served
in
spirit the branches are
also clearly flattened (compare
the branch to the
right
in
Fig. 115) but not
as much
as
is the
case with the dried specimens
; their edges are rounded and they
show no trace of being channelled.
A transverse section
of the thallus shows that the medullary
tissue consists
of irregularly, subdichotomously ramified filaments
running
between
each
other
in
the
mucilage
found
here; they
have rather thick walls and
a diameter
of about 14 ^, but both
thicker and
thinner are
present.
Outwards these filaments bear
Fig. 117.
Galaxaura mar-
ginata
(Sol.).
Transverse
section
of
the
periferic
tissue.
(About
200
: 1).
109
the parenchymatous tissue (comp. Figs. 116 and 117); this consists
of 24 layers
of
cells
of which
the
innermost
are
the
largest;
the
cells
are
nearly
colourless
and
rather
loosely
connected.
From
the
periferal
smaller
cells
in
this
tissue the short
assimi-
lating
filaments
arise.
These are composed
of
the
smaller
sup-
porting,
more
or
less
clavate
cells
with
proportionally
broad
summit and
the
large
assimilating
cells.
The shape of the
last
mentioned is rather variable, sometimes longer, oblong-oval to sub-
cylindric (long. = 57 /*,
lat.
27 //) sometimes shorter, broad oval
(long. = 45
fjL,
lat. = 30 n]
and
they
are
mostly,
as
mentioned
above, provided with a short
apiculus.
The chromatophore
(Fig.
116)
is well developed;
it
is
parietal, placed
in the upper end
of
the
cells,
bell-shaped, with
long
thin
prolongations
downwards
along the walls of the
cells.
In the middle at the top of the cell
it contains a pyrenoid.
Also the supporting
cells contain a chro-
matophore but
lesser developed.
In
the space between
the supporting
cells the chalk
incru-
station
is present as an annular ring giving firmness and cohesion
to
the
thallus.
The
assimilating
cells
protude
freely over
the
chalk
incrustation.
The material examined was
sterile.
M
lle VICKERS
in
her "Liste
des Algues de
la Barbade"
re-
ports Galaxaura apiculata from Barbados.
I have
not
seen
her
specimens but
feel convinced that she has had similar apiculated
specimens
before
her
and
which
I
prefer to
refer as explained
above
to Galaxaura margin ata and not to the Japanese plant, G.
apiculata.
This
plant
has
been found
in shallow water
in a sheltered
locality.
St. Croix: The Harbour of Christianssted.
Geogr. Distrib.
: West
Indies, Atlantic coast
of South America.
Sectio
V.
Vepreculce Kjellm.
11.
Galaxaura occidentals nov. spec.
G.
frutescens,
densa,
stipitata,
stipite
subtereti,
fronde
dichotomo-ramosa,
inferne
subtereti,
superne
complanata,
sic-
cata
canaliculata,
sordide
griseo-olivacea,
membranacea,
super-
ficie
inferne
splenclore
carente,
in
superiori
parte
ssepe
irides-
cente.
Internodia
in
basi
contracta,
2
3 mm
lata.
Papilla
in
110
Fig.
118.
Galaxaura
occidentalis
nov.
spec.
Parts
of the
thallus.
The
figure
to
the
left
from
a specimen preserved
in
alcohol
,
that
to
the
right
from
a
dried specimen. (About
1,5
: 1).
fronde
jnveniliori
rmmerosissimae,
rectse,
clavatae
subcylin-
dricse, summo mucronatee, ca. 40
(
long*
et
11 p.
latse.
The
base
of the
plant
is
a
broad
disc by means
of
which
it
is
fastened
to
the substratum
;
it
consists
of numerous
rhizoidal
fila-
ments.
These are dichoto-
mously
ramified
and
com-
posed
of
cylindrical, nearly
colourless cells, with uneven
walls, about 14
thick.
From
this
basal
part
the
erect
shoots
(Fig.
118)
grow
up
in
all
directions.
These
are
much
branched
and the ramification is more
or
less
regularly
dichoto-
mous.
In
the
lower
part
the
thallus
is
terete
but
it soon
grows
flat;
in the dried plant
the edges
are
mostly
prominent
the
thallus
thus
getting a
ca-
naliculate
appearance
(compare
Fig.
118).
The
branches
are
about 2
3 mm broad
and about 1mm thick
;
the
internodes taper
somewhat below and
are often
jointed
at
the
base.
The plant
preserved
in spirit
is
not canaliculated but
has broadly rounded
edges.
The colour of the
dried
plant
has
a
greyish or dirty olive-
brown
tinge;
in
the
lower
part
the
sur-
face
is dull and
of a
mealy appearance
: in
the
upper
young
parts
often
smooth
and
glossy,
sometimes
shining
like
mother
of
pearl
and
of
a
light
greyish -yellow
colour.
Fig.
119.
Galaxaura
occidentalis
nov.
spec.
a,
transverse
section
of
the
periferic
tissue
showing lobed
cells,
b,
the lowermost
cells in
in the peripheric tissue seen from above. (About
200:1).
Ill
Cutting
a
transverse
section we
find
that the thallus con-
sists
in
the
middle
of irregularly most often dichotomously
ra-
mified
cylindrical
filaments
which run
in all directions in
the
mucilage
found
here;
they have a diameter of about
8// but both thicker and thin-
ner
also
occur.
The peripheral tissue (Figs.
119 and 120) reaches a thick-
ness of about 90,, not count-
ing the
papillae.
The
inner-
most cell-layer has the largest
cells
; these are rounded poly-
gonal,
rather
closely
united,
about
70
tj.
broad
and
40
high
but larger and
smaller
ones
also
occur.
The
cells
in
the
middle
are
smaller,
roundish,
but
larger
lobed
cells are common (Fig. 119 a);
the
cells
in
this
layer
are
about
30
it
high.
Between
these cells and the epidermal ones many and
often
large
intervals
are
present, here
the
chalk incrustation especially is found forming
a
circular
belt round the whole
thallus.
The epidermal
cells
are
closely united
;
they
are
rounded-trigonal
when
seen
in
transverse section (Figs. 119, 120), 5
7-gonal
when seen from above
(Fig. 121).
They are
about
16 n
high and
their
diameter varies
from
18
30 /^. They have a well developed,
campanulate
chromatophore
with
a central
pyrenoid (Figs. 120, 121).
Also in the cell-layer
below the cells have chromatophores but less
developed while the innermost cells have no
chromatophores
at
all.
Finally growing out from nearly
all the
surface
cells we
find
the
onecelled
papilla,
characteristic to the group
of
Vepreculx, by means
of which the
capacity
of
the
assimilating
tissue
is
so
highly increased.
The
Fig. 120.
Galaxaura
occidentalis
nov.
spec.
Transverse section
of the
peri-
pheral
tissue showing the campanulate
chromatophores
with
the
large pyre-
noid above. Below the nucleus
is maid
visible
by
staining.
(About
370:1).
Fig. 121.
Galaxaura
occidentalis nov.spec.
Epidermal cells seen
from above showing
the elegantly shaped
chromatophore with
the pyrenoid
in the
middle.
(About 500:1).
112
Fig.
122.
Gala.r-
aura
occidenta-
lis
nov.
spec.
Papillae
growing-
out
into
hya-
line hairs.
{About
370
:
1).
papillae (Figs. 119 a, 120) protrude
freely over the
surface
of the
thallus and
are not included
in the chalk
incrustation.
In shape
they are
clavate-cylindrical, having their largest
diameter
a
little
above their middle and then
abruptly narrowed
in, running out into a short
apiculus.
They
are
about
40 p. long
and
11 p
broad
in their broadest
part.
They are provided
with a well developed chromatophore
(Fig. 120),
parietal,
cuplike, with
thin
prolongations along
the
wall
of
the
cell
;
in
the
middle
a
pyre-
noid
is
present.
Occasionally
I
have
found
1
2
small
cells
at
the summit
of the
papillae
which
is then rounded and
very
rarely the up-
per
cell
was
also
growing
out
to a
long one-
celled
hair
richly
filled with protoplasm at the
upper end
(Fig. 122).
Antheridial conceptacles (Fig. 123) were pre-
sent
in great numbers. They occur in the young
internodes
and
are
nearly
spherical
bodies
with
an
opening
through the wall
of the thallus.
Their wall
consists
of ramified
filaments
with
larger
cells
growing
closely
together.
From the
innerside of these the richly
ramified
antheridia
pro-
ducing filaments
grow up
in the
cavity. The anthe-
ridial filaments are divided
into
small
cells
of
which
those
at
the
apex
(but
later
on
also
the
other
cells) are transformed
into
mother-cells
for
the
sper-
matia. The antheridia
are
about
8
JJL
long
and
5
//
broad,
oval.
The
anthe-
ridial
conceptacles
have
mostly a diameter of about
200300 n but larger ones
also
occur.
To
the
sectio
Vepre-
culx KJELLMAN
only
refers
four
species
none
of which are from
the West
Indies.
Of
these
G. veprecula
Kjellm. seems
to come
very near to my plant.
I have been
able
te compare my plant
Fig. 123.
Galaxaura occidentalis nov. spec.
Transverse
section
of anantheridial
con-
ceptacles.
(About 200
: 1).
113
with the
original specimen
from Madagascar and sent
to KJELL-
MAN from E. BORNET under the name of G. marginala.
Both plants
grow
in dense tufts.
But my plant is not so much incrusted with chalk, the thallus
is thinner, the
internodes
are
less
broad
at their base.
Further
G. veprecula
differs
from my species by having an
entirely
dull
surface and by being more
light yellow-green with a reddish tinge.
To judge from KJELLMAN'S description and
figures the anatomical
structure seems to come very near
in
both
plants;
but the
pa-
pilla?
in my
plant
are
longer and
relatively more
slender than
those
in KJELLMAN'S plant which besides have also often a round-
ish apex.
And
G. infirma Kjellman
from Sandwhich Island which has
also the internodes somewhat narrowed
differs from my plant
in
its
thicker,
dull, not
shining and
rather
rugose
thallus
and by
the
different
form
of the
papillas.
However, the
original
speci-
mens
are
some
small
fragments
and
a
comparison
is
therefore
difficult.
The two
other
species, Galaxaura hystrix Kjellm. and Galax-
aura ventricosa
Kjellm. seem to show more differences.
In a paper: "Notes on the
species
of Liagora and Galaxaura
of the Central Pacific" 1
) F. K. BUTTERS has described a Galaxaura
spec, which seems to come very near to my plant; but to judge
from the very short description some minor differences are present
:
the
Pacific
plant
seems
to
be more
distinctly
contracted
and
jointed
at the base of the internodes and
the
size and shape
of
the
papillae
also show some
differences.
Galaxaura
occidentalis
I
have
found
only once
in
shallow
water and
in
sheltered
place;
in the
collections
of
alga?
in
the
Botanical
Museum,
Copenhagen,
two
old
specimens
are
found,
one
from
St. Croix
and
another
with
the
indication
"Antillis
1836".
St. Croix: The harbour
of Christiansted.
In "Minnesota Botanical Studies",
Vol. IV, part
II, Minneapolis 1911,
p.
183.
114
Fam. 3.
Gelidiacece.
*
Gelidium Lamour.
1.
Gelidium corncum (Huds.) Lamour.
LAMOUROUX,
J., Essai
.
.
.
Thalassiophytes (Annales du Museum,
vol.
XX,
1813,
p. 128).
BORNET,
E., Les Algues de P. K. A. SCHOUSBOE,
1892,
p.
270.
Fucus corneus Huds., Fl. Anglica,
1778,
p. 585; TURNER,
Fuel,
vol. IV,
1819,
p.
146.
var. pinnata (Huds.) Turner.
TURNER,
1.
c.,
p. 146,
tab. 257,
fig.
d.
Fucus pinnatus Huds.,
Fl. Anglica, tome
II,
1778.
p. 586.
Gelidium cserulescens Crouan
in MAZE
et SCHRAMM, Algues de Guade-
loupe, 187079,
p. 109.
COLLINS,
F., The Algae
of
Jamaica,
p. 252.
Non
Gelidium caerulescens Kutz., Tab. Phycol.
vol. 18,
p. 19, tab. 56.
The
plant
(Fig.
124)
I
here
refer
to
this
species seems
to
agree
fairly well with the above quoted
figure
of TURNER.
It
is
the same which
the brothers CROUAN,
1.
c. p.
199, have
referred
to Gelidium cserulescens Kutz. By means
of an
original specimen
of
MAZE
et
SCHRAMM'S
Algues
de
la
Guadeloupe
I
have
been
able
to
state
its
identity.
COLLINS
has found
the same
plant
(distributed
in Phycotheca Bor. Am,, Nr. 783) in the collections of
algee
from
Jamaica which
he
has worked out and
in
his publi-
cation: "The Algae
of Jamaica" (Proceedings
of the Amer. Acad.
of Arts and
Sciences,
vol. 37,
1901) he
calls
it
(p. 252) Gelidium
cserulescens Crouan.
Concerning
the
use
of
this name he adds
:
"By
the
kindness
of
Dr. BORNET
this
plant has been compared
with
authentic
specimens from Guadeloupe, and
it
is the
plant
referred
to by MAZE & SCHRAMM, Algues de Guadeloupe,
p. 199.
Whether
it
is
the
plant
of
KUTZING, Tab.
Phyc.,
vol. XVIII,
pi. 56, from New Caledonia,
is
not
certain."
As
it
seemed
to
me
of great
interest
to know how
far KUTZING'S plant and that
of CROUAN
agreed
I
sent
one
of my
specimens
to Mme WEBER
and asked her to do me the favour of comparing my plant with
the type
specimen
in
Herb. KUTZIXG.
Mme WEBER
obliged me
by making
such
comparison
and
she
tells
that there
is only a
single
specimen
in
Herb. KUTZING
namely
the
one
figured
in
"Tabulae";
the
specimen
is much
like
the
figure,
the
shade
of
the colour may
be a
little darker
in
this plant but that
is the
only
difference.
Further Mme WEBER
writes:
"The
specimen
bears
tetraspores
at
the
top
of
almost every branch.
Can
this
115
be the reason why
all the tops
are blunt?
I
don't know and
I
should want more specimens to judge the
species well.
As mat-
ters stands my type specimen
differs from the specimen you sent
me,"
And Mme WEBER
adds
that
she
thinks
that
the West
Indian
plant
is very much
like Gdidium corneum to which
spe-
cies
I
also think
it may
rightly be
referred.
As mentioned above my specimens (Fig. 124) agree well with
TURNER'S
figure
of
his
var.
g. pinnata
yet they
are somewhat
smaller and
often
only
bipinnate.
The West
Indian specimens
too
are
very
similar
to
a
specimen
of Gelidium
corneum
from
Ceylon
distributed
by
HARVEY
("Ceylon
Algae",
No. 31).
The
specimens
found
are about 5 cm high. The
thallus
is
flat, reaching
a
breadth
of
about
2 mm,
seldom more.
The apices
are blunt with a somewhat
sunken growing point. The
thaJlus
is
mostly
bipin-
nate, seldom tripinnate and
the ramification upon the
whole
is
rather
irregular
and
parts
of
the
thallus
are
often
destitute
of
branches.
A
transverse
section
agrees with the description
of HAUFE 1
). The
tissue consists
of a medullary
layer and a
cor-
tical
layer.
The former consists
of
rather long cylindric colour-
less cells. The cortical
layer, on the other hand,
is composed
of a
few layers of red-coloured, short cells, radially arranged round the
periphery
of
the
thallus.
Between
the
cells
of
the
medullary
layer the hypha?-like filaments characteristic of Gelidium are found
in abundance.
The material was
sterile.
This
species
has
been
found
only
in
the
more
sheltered
places.
Fig.
124.
Gelidium corneum
(Huds.)
La-
mour.
Habit of the
plant.
(About 2:1).
1
) HAUFE, Fr. E., Beitrage zur Kenntnis der Anatomie und theilweise der
Morphologie einiger Florideen.
Inaugural-Dissertation.
Gb'rlitz 1879.
8*
116
Fig. 125.
Wrangelia Argus Mont.
Disc-
shaped haptera growing out from a basal
cell in a ramulus found in the lowermost
prostate part of the thallus.
The upper
large cell in the main filament is broken
off.
(About 150:1).
Wrangelia
plebeja
J.
Ag.,
Spec.
Alg.,
vol.
II,
pars. 3, 1863, p. 707: Epi-
crisis,
1876,
p. 623.
This species especially differs
from Wiwngelia penicillata
in
its
small size being seldom more than
1
! 1
/ 2 cm
high, the acute ends
of
the
filaments
composing
the
ramuli
and
the
lack
of a dense
cortical
layer.
The West
Indian
specimens
are
as
to
their
external
habit
much
like
figure
4/
of
MON-
TAGNE,
1.
C.
Wrangelia Argus
is a
littoral
alga growing even
in rather ex-
posed
places.
It
is fixed to the
substratum by means
of nume-
rous,
often very robust
hapterse
which grow out
from
the
basal
cells
in the ramuli found
in the
lowermost more or
less prostrate
St.
Croix:
in
several
lo-
calities near Christiansted in the
harbour, Long Reef, Lt. Princess.
Geogr. Distrib.: Warmer
parts
of
the
Atlantic
Ocean,
Mediterranean
Sea,
Ceylon
etc.
Fam.
4.
Wrangeliacece.
Wrangelia C. Ag.
1.
Wrangelia Argus Mont.
MONTAGNE, J. F. C., Sylloge
generum
specierumque
Crypto-
gamarum, Paris 1856,
p. 444.
Griffithsia Argus
Mont,
in
WEBB et BERTHELOT,
Hist. nat.
des
iles Canaries, vol. Ill, Sectio
III, Paris 183650,
p. 176,
tab.
8,
fig.
4.
Fig. 126.
Wrangelia Argus Mont.
Upper end
of a branch with
ra-
muli and tetrasporangia.
(About
80
: 1).
117
parts
of the principal
filaments
(Fig. 125).
As mentioned above,
the
large
cells
in
the
principal
filaments
lack
a
dense
cortical
layer,
yet an attempt
at
this
is
present,
as from the basal
cells
in
the ramuli some very ramified
filaments grow out and bend
themselves round the large cells in the principal filaments (Fig. 125).
The
cells
in
the
principal
filaments
are about
225 //
broad
and about four times
as
long.
The
ramuli
are more robust than those
in Wrangelia peni-
cillata
which
is
the
natural
outcome
of
the littoral occurrence
of this alga
; the single
cells of the ramuli are
proportionally
short
and
broad,
the
fila-
ments become evenly
narrower towards the
apex and end with a
short,
acute,
conical
cell
(Fig. 126).
In
this
species
tetraspores only were
found (Fig. 126). Like
the tetrasporangia
in
Wrangelia
penicillata
they
are
terminally
placed
upon
the
ra-
muli
and
are
sur-
rounded by short
fl-
laments more
closely
pressed
to the
tetra-
sporangia than
in
Wrangelia penicillata.
They are tetrahedrally
divided and
their diameter reaches about 60
tu.
In referring the Wrangelia plebeja of J. AGARDH to MONTAGNE'S
species
I make
this
statement
upon
specimens
determined
by
AGARDH
and
collected
at
St.
Croix
by
ORSTED.
Certainly
the
description
of MONTAGNE
is
not
especially
exhaustive
but
his
figures
are
of much
help.
This species has been found at St. Thomas:
In several
places
in the
harbour and in Store Nordsidebugt.
At St. Croix
it
is as mentioned above
collected by DRSTED.
Geogr. Distrib.
: West
Indies. Canary
Isles.
Fig. 127. Wrangelia bicuspidata nov. spec.
Habit
of a Plant -
(About natural
size).
118
2.
Wrangelia bicuspidata nov. spec.
Frons mediocris,
ca. 7 cm
alta,
csespitosa, ramosa,
ecorticata
vel
in
ramis
principalibus
subcorticata,
in
superior!
et
inferior!
parte cellularum magnarum
filis decurrentibus
et
assurgentibus,
ex
cellulis basalibus ramellorum
ortis, munita.
CellulaB in ramis principalibus permagna?, subcylindricse, 120
fj.
latae
et
10-plo
longiores,
in
superiori
parte ad genicula verticilla-
tim ramellosss, ramellis mol-
lissimis,
pluries dichotome
divisis,
a
basi
ad apicem
leniter
tenuioribus,
termi-
nali articulo generaliter bi-
cuspidato, cellulis
in parte
basali
ca. 50 //
latis, supre-
mis
ca. 1 p.
latis.
Fructificatio ignota.
All the specimens found
were sterile
so
in
referring
them to Wrangelia
I have
only
had
the
vegetative
thallus to rely on, but
this
shows so much
likeness to
the other species
of Wran-
gelia that
I have no
hesi-
tation
in
referring
it
to
this
genus.
As
being
especially
characteristic
of
this
plant may
be
mentioned
Fig. 128.
Wrangelia bicuspidata nov. spec.
Part
of
a main
branch
with
the
basal
parts
of
the
branchlets from Avhich
fila-
ments grow out upwards and downwards.
(About 60
: 1).
the
fact
that
the
cor-
tical
layer
is
not
much
developed
and
that
the
apices
of
the assimilating
filaments
mostly
end
in two
short
acute
conical
cells.
Wrangelia bicuspidata
is a
sublitoral alga growing
in
rather
deep water, 20
30 meters
or more.
It
is an epiphyte,
as
in the
case
of
Wrangelia
penicillata
found
upon
different
large
algae,
e. g. Caulerpa, Halimeda, Arrainvillea etc. and
is
fixed to these by
means
of thin rhizoids growing out from the lowermost parts of
the filaments.
The plant has a beautiful rosy colour and forms
loose, flabby
tufts up to seven cm or more
in height
(Fig. 127). The principal
119
filaments
consist
of
very
long,
nearly cy-
lindrical
cells (comp. Fig. 128) about 120 //
broad
and about ten
times
as
long; these
cells are thickest near the base, taper slowly
upwards
growing somewhat
thicker
again
at
their uppermost ends and
have
rather
thick
walls.
At
the
upper end
these long
cells
carry
a
whorl
of
branchlets.
These
are
repeatedly
subdichotomously
ramified
growing evenly thinner towards their apices
which end in a single or, usually two, seldom
three
short
conical
cells
(Fig. 129).
From
the
basal
cells
of
the
branchlets
several
ramified
filaments grow out, some upwards
some downwards, bending themselves round
the
large
cells
of
the
principal
branches
(Fig.
128).
In
the
upper
parts
of
the
branches where
the
cells
are
shorter they
often cover the whole
cell
(Fig. 130) while
in the
older parts
it
is only the upper and
lower parts which they surround.
As a rule
those
filaments
lie
quite
loose round
the
cell (compare
Fig. 128).
The branchlets are as
is commonly the
the case in Wrangelia crowded together
in the upper, young ends
of
the
branches,
lower down
the whorls
of
branchlets
are more
distant
in
accordance with
the
lengthening
of the large
central
cells.
In the lowermost part of the branches
the branchlets
fall
off.
Compared
with
Wrangelia
Argus
our
plant reminds
of
this
species
as
to
its
loose
cortical
layer
but
differs
from
it
in
its
much
larger
and
more
loosely
constructed
thallus and
further by the bicuspidate ends
of the branchlets.
And Wrangelia penicillata especially differs
from this species by its continuous cortical layer
in the principal filaments, by the blunt ends
of the branchlets, by its much
larger size etc.
Fig. 130.
Wrangelia
Wrangelia bicuspidata has been found
in
bicuspidata nov.spec.
^Q
sublitoral
region down
to
a
depth
of
Part of a young
branch. (About 80:1).
about 30
40 meters.
Fig.
129.
Wrangelia
bicuspidata nov. spec.
Apices
of
branchlet.
(About 60
: 1).
120
Found in several places
at
St. Jan
in the sound between
this island
and
St. Thomas where
it seems
to be common.
3.
Wrangelia
penieillata
C. Ag.
AGARDH,
C., Spec. Alg. II, p. 138.
AGARDH,
J., Spec. Alg.
II, pars
III,
p. 708;
Epicrisis, p. 623.
DERBES
et SOLIER, Memoire, p. 71,
pi. 18, figs. 6
8..
KUTZING, Spec., p. 664.
HARVEY, Nereis Bor.-Am., Part II,
p. 143,
tab. 34 B.
BORNET
et THURET, Notes algologiques, Fasc.
II,
1880,
p. 183
;
pi. 48.
ZER-
LANG,
O. E., Entwicklungsgesch. Untersuch. liber die Florideen-Gatt. Wran-
gelia und .Naccaria (Flora,
47,
1889,
p. 371).
Gnffithsia penieillata Agardh, Systema Alg.,
p. 143.
Dasya
spinella Duby, Second "m^moire
sur
le
groupe
des
C6ramies,
p.
13,
tab.
II,
figs. 3,
4, 5 and tab.
Ill,
figs.
1, 2.
In the West Indian seas this plant attains a great size especially
when it is growing in deep water.
Several of the specimens reach a
height of 20 cm or even more.
The specimens growing in shal-
low water are smaller and more
robust and more like the Euro-
pean specimens while the speci-
mens from deep water are more
flabby, thinner and
in
all
re-
spects more elongated. As to the
American form see HARVEY, 1. c.,
where a description and
good
figures of this plant are found.
ZERLANG
has
1.
c. given
a
very
detailed
description
of
the
development and
structure
of
this plant to which
the reader
is
referred.
1
shall only mention
briefly that the main filaments
in
an
early stage
of
development
become bare
at
their base while
higher up
they
carry
the
verticillate
branchlets
at each
joint.
From
each
of
these
whorls
a
smaller
branch
issues
and
these
branches are regularly alternating.
Some of these branches grow
out
into long branches and serve to form the
ramification
of the
thallus, most
of them
in the sterile plant soon
die away and
fall
off;
in the
fertile plant, on the other hand, they carry the organs
of
fertilization and
last
longer.
The branchlets
are subdichoto-
mously branched, thin and
soft.
At the
apices
of the
branches
the
branchlets
are
bent
upwards
and
more
or
less
cover
the
growing
point
of
the
branch,
giving
all
the
short
branches
a
penicillate appearance.
The ends
of the
lilaments
in the ramuli
are blunt.
Fig. 131.
Wrangelia penieillata C. Ag.
Part
of a plant with tetrasporangia.
(About 200
: 1).
121
All
the
larger
filaments
are covered
with
a
cortical
layer
(comp. Fig. 132)
formed by the
rhizoids growing
out
from
the
base
of the branchlets;
in the young parts
of the branches this
cortical layer
is not yet developed.
The
tetrasporangia
(Fig. 131)
of which
DERBES
et SOLIER,
1.
c., pi. 18,
fig.
7,
give
a
figure are placed
terminally upon
the
short ramuli.
The
cells from w
rhich the tetrasporangia originate
give
rise
also
to
some short filaments which
are more
or
less
curved round the tetra-
sporangia forming in this
way a kind of involucre.
The
tetrasporangia
are
spherical,
tetrahedrally
divided;
their
diameter
reaches a length of about
15fjt.
The branch which
carries the tetrasporan-
gia-bearing
branchlets
are,
as
pointed out by
ZERLANG,
mostly
with-
out a
cortical
layer.
The
antheridial
stands
(Fig.
132)
are
spherical bodies termin-
ally
placed
upon
the
ramuli
and, in a similar
way
as
the
tetraspor-
angia,
surrounded
by
curved cells growing out
from the cell which carry
the antheridial stand. This
consists
of numerous short filaments
radiating out from
the
middle
of the stand and
at
the end
of
which the spermatia are formed. The diameter of the antheridial
stand reaches a length
of about 60,. DUBY has
1.
c., pi.
II, fig. 4
given
a
figure
of
a
branch
with
antheridial
stands.
In
the
branches W'hich carry the ramuli with antheridial stands
I have
mostly found the cortical layer very well developed.
The
cystocarps
are
spherical
and
terminally
placed
upon
short branches.
Regarding their shape and development upon the
whole BORNET
et THURET, SCHMITZ and
especially ZERLANG have
given detailed
descriptions and the
first mentioned have further
given
very
fine
illustrations,
1.
c., pi. 48.
To these descriptions
Fig. 132.
Wrangelia penicillata C. Ag.
Part
of a male plant with
antheridial stand.
(About 200:1).
122
and
figures
I must
refer
for
details.
The few trichogynes
I have
seen seem to be somewhat
longer than those drawn by BORNET
and ZERLANG.
The tetraspores, antheridia and cystocarps occur
in separate
individuals
; these organs were found
in the months of February
and March.
This
species
seems to
be common
in the
sublittoral
region
down
to
a depth
of about 30 meters
and
is
found
as
an
epi-
phyte upon
larger
alga?,
e. g. Caulerpa,
Penicillus,
Udotea
etc.
St. Croix: Near Buck Island.
St. Jan:
in many
places
in the sound
between
this island and St. Thomas.
Geogr. Distrib.
:
Mediterranean Sea;
the warmer parts of the Euro-
pean and American coasts
of the Atlantic.
II. Cryptonemiales.
Fa/7?.
1.
Grateloupiacece.
Halymenia
C. Ag.
1.
Halymenia Floresia (Clem.) Ag.
AGARDH,
G.,
Spec. Ag.
I,,
p. 209;
Systema,
p. 243.
AGARDH,
J.,
Alg.
Mediterr. & Adriat., p. 96; Spec. Alg.,
II.,
p. 205;
Epicrisis, p. 138.
KUTZING,
Spec. Alg.,
p. 716;
Tab. Phycol.,
vol. 16,
pi. 8889.
HARVEY, Nereis Bor.-
Am., vol. II, p. 193.
BERTHOLD, Die Cryptonemiaceen des Golfes von Neapel
(Fauna und Flora des Golfes von Neapel,
XII. Monographic,
1884).
Fucus Floresius Clemente, Ensajo sobre
las variedades, 1807,
p. 312.
TURNER, Fuci,
pi. 256.
Of
this
species
I
have
collected
a
few
specimens
some
of which are rather large reaching a length up
to 40 cm.
They
are
all
very much
ramified
and
compared with
the
specimens
distributed
in
Phycotheca
Bor.-Am., Nr. 298
thinner
and
flab-
bier and
of a
paler
rosy
colour.
This
is most probably due to
their development
in rather deep water.
On the other hand my
plants
are much
like
a
specimen
from
Jupiter
Inlet,
Florida,
collected and most kindly sent to me from Mrs. G. A. HALL.
Halymenia Floresia is
fixed
to the substratum by means
of
a small
disc.
Immediately above
this
the thallus
is
terete, but
it very soon
becomes
flattened
and passes evenly over into the
123
leaf-like
thin
part
of the
thallus.
This
is much ramified.
The
branches
or
proliferations
issue along the margin
of
the
frond
and
these are again
branched
in
the
same way several
times;
the ultimate ramifications
in my specimens
are long and narrow
and taper evenly against the summit.
A transverse
section shows that the medullary layer
is of a
very
loose
consistency
with
very much
mucilage
between
the
hypha3-like
filaments
of which
it
consists
and
between which
thicker ones grow out
in
all
directions.
The
cortical layer con-
sists
of more
roundish
cells; these
are
small,
oblong-cylindrical
and
closely placed
at the
periphery, large and more
loosely
ar-
ranged innermost.
Where the
cortical layer passes over into the
medullary
tissue,
scattered
starlike
cells
are
found
with
long
thin prolongations, radiating in
all directions and
fusing together
with those from the neighbour
cells.
The specimens found have tetrasporangia.
These occur scat-
tered over the whole surface and are formed
in the cortical
layer.
They are cruciately divided but often very
irregular.
They are
about 25
30^
long.
This
species
has
been found
in
several
places
in the sound between
St. Jan and St. Thomas in depth down to 30
40 meters.
Geogr. Distrib.
:
Mediterranean
Sea, warmer
parts
of
the Atlantic
Ocean, Canary
Island, West Indies
etc.
Grateloupia C. Ag.
1.
Grrateloupia
filicina (Wulf.) Ag.
AGARDH,
C., Spec. Alg.,
p. 223; Systema,
p. 241.
GREVILLE, Alg. Brit,
p. 151,
pi. 16.
HARVEY, Phycol. Brit.,
pi. C.
KUTZING, Tab. Phycol.,
vol.
XVII,
pi.
22.
J. AGARDH, Spec.
II,
p. 180;
Epicr. p. 153.
Fucus
filicinus Wulf.
in
Jacquin,
Collectanea,
vol.
Ill,
1789,
p. 157,
tab. 15,
fig.
2. TURNER, Hist. Fucorum, pi. 150. Esper, Icones Fucorum, pi. 67.
Grateloupia
filicina
is a
littoral
alga which commonly grows
in
more
sheltered
places
in
quite
shallow water.
BERTHOLD 1
)
points
out
that most
of the species
of Grateloupia found
in the
Gulf of Naples were found
in water polluted from the town.
In
such
places
Grateloupia
filicina
also
occurs
in
the West
Indies
but furthermore
it
is much common
in
quite
clear water and
as
it
is
often
fixed
to
small
stones
scattered
upon
the
dazzling
white
coral sand
it grows
in very intense
light.
In such places
BERTHOLD,
G.,
Die Cryptonemiaceen
des
Golfes von
Neapel
(Fauna
und Flora des Golfes von Neapel, XII Monographic,
1884).
124
the
plant assumes
an
often
quite
bluish-green
colour
while
in
places more protected
against the
light
its colour
is a dark red-
brown
or red-violet; by drying the blue-green specimens assume
mostly a dark red-brown
colour.
The ramification
is monopodial.
It
is a very variable plant
;
in
some
specimens
the
branches
are
long
in
others
short,
in
some
the
length
of
the
branches
grow evenly shorter upwards
in
others they are longer and more vigorous upwards and much
ramified.
Some specimens have a proportionally broad
thallus
in
others
the filaments
are
nearly thread-like.
In some specimens
the main
filament bears along
its whole length rather short un-
divided branches.
KUTZING has figured
several of these forms in
his Tabulae Phycologica?.
A
transverse
section
shows
the
structure commonly
found
in Grateloupia. The medullary layer
is very loose
in the middle,
denser towards
the
periphery where
it goes
rather
evenly over
into the cortical
layer.
The filaments
in the medullary layer are
about
8/4
thick; they are
irregularly
subdichotomously ramified
and
felted between each other.
The
cortical
layer consists
of short
closely packed filaments
whose innermost cells are nearly spherical, oblong to subcylindric
at the
periphery.
The tetraspores are formed
in
great numbers over the whole
thallus
in the
cortical layer; they
are
cruciately divided.
The
antheridia and
cystocarps
occur
in
the same
plant
as
pointed out by BERTHOLD.
The antheridia are formed of the peripheral cells in the cortical
layer as a kind
of outgrowth from these; the spermatia are small
spherical bodies about
4
5 p
in diameter.
The cystocarps occur more or
less over the whole
surface
of
the
thallus.
They are spherical
bodies about
180
fj.
in diameter
and reach far into the medullary tissue. The wall is well developed
formed by filaments growing out from the auxiliary cell
filaments.
The cystocarps
discharge by means
of a
pore through
the
cor-
tical
layer.
The carpospores are densely crowded together forming
a nearly spherical body.
They
are about
18
20 p
in
diameter.
With the exception
of the most exposed
localities
this species
is com-
mon along the shores of the Danish
Isles.
Geogr. Distrib.
:
Seems
to occur in
all warmer
seas.
2.
Grateloupia diehotoma
J. Ag.
J.AGARDH, Algae mar. Mediterr., 1842, p. 103.
KUTZING, Spec. Alg., p. 732;
Tabulae Phycologicse, vol. XVII, tab. 28,
figs, c
e.
J. AGARDH,
Epicr., p. 152.
125
As
to
their outer habit the specimens found show much
like-
ness to the
figures
c and d
of KUTZING quoted above.
A transverse
section
(Fig. 133)
of the
thallus
reveals the
fact
that
the
medullary
tissue
is very loose and
open
in the middle
more dense outwards.
It
consists
of thin
cylindric
filaments very
irregularly,
often
stellately, branched and woven together.
Their
diameter
is
variable,
often
5
6
p.
thick.
Towards the periphery
they grow tkicker and mostly run more or
less
parallel with the
surface of the thallus. From these filaments the cortical layer arises.
This consists of short dichotomously ramified filaments placed verti-
cally upon the surface of the thallus. The innermost cells in this layer
are
largest, nearly spherical,
about
ftp
thick; from these
is an even transition to the
peripheral
ones
which
are
subcylindric about
4// thick
and 8^
long.
The
tetraspores
are
found
in
great
numbers
in
the
cortical
layer over
the
whole
surface
of
the
thal-
lus.
They
are
cruciately
divided and about 27 /* long
and 14 // broad.
The
cystocarps
occur
scattered, more or
less, over
the
whole
surface
of
the
plant. They are nearly sphe-
rical about 180
fj. broad; the
cells
in the wall
are
of very irregular shape. The carpospores are
formed
in
great
quantities and
are about
14 /* broad.
This
species
is
littoral;
it occurs
in
quite shallow
water
in
rather
exposed
places
where
it
is
dashed
by the waves.
Like
Gr. cuneifolia
it
is
found abundantly
in
polluted water near the
town but
it
is
also found
in quite
clear water.
St. Thomas: The Harbour near Charlotte Amalie, the Hurrican Island.
Geogr.
Distrib.
:
Mediterranean
sea, warmer
parts of
the Atlantic
Ocean.
3.
Grateloupia
cuneifolia
J. Ag.
AGARDH,
J., Algologiska bidrag in Ofversigt
k. sv. Vetensk.-Akad. For-
handl. 1849,
p. 85; Spec. Alg.,
vol.
II,
p. 181;
Epicrisis,
p. 154.
MONTAGNE,
Sylloge
gen. spec. Cryptog.,
p, 433. KUTZING,
Tab. Phycol., vol.
17,
tab. 34.
Fig.
133.
Grateloupia
dichotoma
J. Ag.
Transverse
section
of
the
thallus with
tetrasporangia.
(About 550
: 1).
126
This
species
is
a marked
littoral
alga.
It
grows
together
with
Ulva
etc. near
the
surface
of the
sea
in
places where the
waves
constantly
dash
the
rocks.
The
thallus
is
tough
and
elastic with
a glabrous and
lubricous
surface, very apt
to
grow
in such
localities.
The
specimens
collected
(comp. Fig. 134)
reach
a
length
of
up
to 40 cm and more. They are fastened
to the substratum by
means
of
a
small
disc.
Immediately
above
this
the
thallus
is
terete
but
it
soon
be-
comes
compressed
and
passes
evenly
into
the
ribbon -like
or
leaf-
like
frond.
This
differs
very
much
in
shape,
sometimes
it
is
more
narrow, sometimes broa-
der 1
)
;
some
specimens
are
not
divided
at
all
but
this
is
rare;
most
of
the
specimens
are
more
or
less
lacerated
or
what
is
more
common bear numerous
smaller and larger
pro-
liferations
along
the
margin.
Towards
the
summit the thallus itself
and
the
proliferations
are evenly narrowed and
run out
often into long
thin prolongations.
The
margin
of the whole frond
is more
or
less undulated. The colour
is a deep
red-violet.
KUTZING'S above quoted
figure seems to me to give a
fairly
good
illustration
of the
plant.
A transverse
section
(Fig.
135)
of
the
thallus shows that
a
marked
difference
between the medullary tissue and the
cortical
layer
is
present.
The medullary tissue consists of more or
less cylindrical much
Fig.
134.
Grateloupia
cuneifolia
J. Ag.
A
smaller much
divided
plant.
(About
half
natural
size).
J
) The broadest specimens in my
collection are
4
5 cm broad.
127
ramified
filaments running between each other
in
all directions
in
the mucilage found
here.
In a longitudinal
section
it
is seen
that the medullary
cells
are very irregularly branched
often more
or
less
starlike
(Fig.
136);
the
breadth
of
the
cells
is
also
very
vari-
able
and
this
is
also
the
case
regarding
the
length
of
the
cells.
The
develop-
ment
of these
starlike
cells
is
just
the
same
as
is
de-
scribed by BERTHOLD
(1.
c.,
p.
2)
for
Halymenia.
The
filaments
having
got
some
length
swell
at
the
end
and
from
this
thickened
part filaments grow out in all
Fig.
135.
Grateloupia
cuneifolia
J. Ag.
Transverse
section
of
the
thallus with
tetrasporangia.
(About 550
: 1).
directions
; the ends of some
of these filaments meet other
similar ones and fuse together
with them
or their ends swell and
give
rise to new star-like cells.
The
cortical
layer
is
composed of short dichoto-
mously ramified
filaments.
The
innermost
cells
in
these
are
the
largest and
more
irregularly
shaped,
the
outermost
small
oval
to
subcylindrical
8
9
fj.
long and about
3
// broad
and rather closely packed
together.
The tetrasporangia (Fig.
135)
are
formed
in
the
cortical
layer
and
occur
scattered
over
the
whole
surface
of
the
thallus.
They
are
cruciately
divided
about
30
/j.
long and
19
// broad.
Among
the
dried
specimens
a
single
cystocarpic
one
was
found. While the tetrasporic specimens have quite a smooth
sur-
Fig.
136.
Grateloupia
cuneifolia
J. Ag.
Star-like
cells from
the
medullary layer.
(About 250:1).
128
face
the
female
plant
has
a
very uneven
warty
surface.
Th(
cystocarps
are
found
spread
over
the
whole
thallus;
they
placed rather deep in the medullary tissue, are nearly spherical am
open by means of a pore through the
cortical
layer.
Plants with
tetraspores and cystocarps were met with in the months December
to March.
This
species
has only been
found
in very polluted water at
the town Charlotte Amalie.
St. Thomas: The harbour.
Geogr. Distrib.
: West
Indies.
. 2.
By Mme A. WEBER-VAN BOSSE.
Contarinia Zanardini.
1.
Contarinia Magdae nov. spec.
Thallus
totus
substrate
adha3rens, ad
basin
calcareus,
con-
stahs hypothallo
et
perithallo.
Hypothallus constat
filis
ramosis,
parva
flabella efficientibus.
Perithallus constat
fiiis
erectis, dicho-
tornis, quorum
cellule peripheriam versus decrescunt.
Cellulae
altse
40,
20,
12 //,
latse
20,
16,
12 u.
Tetrasporangia
in
soris
ex
apice
fili
transformata,
clavato-
obovata,
irregulariter cruciatim divisa;
alta 36, 40/*, lata 16, 20^.
Contarinia
Magdse
1
)
is the
first alga
of this genus
collected
in the West Indies were
it was gathered by Dr. TH. MORTENSEN in
the "Sound" between St. Thomas and St. Jan.
It is growing on and
entirely enveloping a hard mass of small stones and coral that had a
diameter of 3 cm. Of its colour it is impossible to judge for the spe-
cimen is preserved in alcohol.
It is distinguished from C. Peyssonne-
li&formis by
its
frond,
calcified
at
the base
and
only free from
carbonate
of lime
in
its upper part, whereas the whole frond
of
C. Peyssonneliseformis
is
fleshy
(carnosa).
The
size
of
the
cells
shows another difference
between
the two
algee:
the
cells
of
C.
Magdse have
a
breadth
of
rarely
40, mostly 20 /*,
at the
base,
diminishing towards the
periphery where they
measure
often 20
and
even 16 and 12^.
The height
of the
cells
at the base and
the middle
of the filament
is sometimes
2
mostly
l l
/ z
as high
1
) So
called
in honour
of Mrs. BORGESEN, the graceful wife and compa-
nion
of the explorer of the
Danish West-Indian
islands.
129
as broad
or isodiametric
; towards the periphery the
cells
are, as
a
rule,
as
high
as
broad
or a
little less.
Seen from above the
peripheral
cells have a diameter
of d= 20^.
The
cells
of C. Peys-
sonnelixjormis have a
breadth
of 20
12^
at the
base, lessening
upwards to 8 and to 5 p at the top
; they are from l x
/ 2 to
4 times
as high
as broad.
The
vertical
rows
of
cells
of
C. Magdse
loosen
themselves
from
each
other
under very
slight
pressure
after
decalcification
and
only
their
basal
cells
remain
fastened
together.
This
will,
probably
be
in consequence
of the
disappearance
of
the
carbonate
of
lime.
There
are
lateral
pores
be-
tween
the
cellrows,
but
the
pores
are very delicate and
do
not
tend
to
make
the
frond
much
firmer.
C. Peyssonneli&fortnis has no carbo-
nate
of
lime between
its
cellrows,
which do not loosen themselves from
each
other
under
slight
pressure
;
the frond
is
soft and
fleshy
to the
touch after having been moistened.
The
tetraspores
of
C.
Magdae
are
born
in
sori
at the top
of the
vertical
cell-rows
(Fig.
137);
they
divide
in
a
cruciate
way,
but the
divisions
are
often
irregular
and
sporangia with two and three spores
only, are not rare. They are covered
by a pretty firm cuticula, that seems
to tear off at maturity of the spores.
The
sporangia
have
a
height
of
36
40
1620
.
Fig.
137.
Contarinia
Magdse
n. sp.
a. section through vege-
tative
part
of
thallus
in
full
growth,
with
the
cells
in
the
higher part dividing repeatedly.
b.
section
through
part
of
a
soruswith tetrasporangia at the
top of the filaments.
(120:1).
and
a
breadth
of
Found
in
the "Sound"
between
St.[ Thomas and
St. Jan by
Dr.
MORTENSEN.
Fam. 3.
Squamariacece.
By Mme A. WEBER-VAN BOSSE.
When treating of the Squamariaceae. of the "Sealark" expedition,
I
divided the
Peyssonnelia
into three subgenera:
1. Peyssonndia
s.
s. or Eupeyssonnelia with a hypothallus consisting in the main
of
straight
filaments, running close to one another
in a horizontal
9
130
'
Fig. 138.
Peyssonnolid
simulans n.sp. Straight
running filaments of the
hypothallus.
(160:1).
direction
over
the
substratum
(Fig.
138),
2.
Cruoriella
with
a
hypothallus
of
curved
filaments
running
in
little
fan-shaped
or
broad-lanceolate groups over the
substra-
tum
(Fig.
139)
and
3.
Ethelia
with
no
hypothallus
but a mesothallus that gives
off branches both downward and upward.
This
division
proved
very
useful
while
working out the Peyssonnelia
of
Dr. BOR-
GESEN.
In
his
collection
species
of Peys-
sonnelia and
Cruoriella are
numerous but
the
subgenus
Ethelia
is
wanting,
it
has
till
now
been
only
found
in
the
East-
Indian
seas and
in the Mediterranean.
P.
squamaria,
the
well-known
inhabitant
of
the
last-named
sea, has a true mesothal-
lus
though
the
perithallus
inferior
is
re-
duced to only one layer
of
cells.
It
is
a
well-known
fact
that
alga?
have
a
great
variability and
in how
far
the Peyssonnelia are
subject to
this general
law,
is
still an open
question, for this group of plants has relatively been
little studied.
We know that the circular or lobed fronds can be membranaceous
(P. rubra),
coriaceous (P. squamaria),
or calcareous
and
hard
as
stone (P. polytnorpha), but there are also
other forms not entirely calcareous neither
coriaceous
; we will have to speak of such
a species
in the
following pages.
A frond
will, as a
rule, increase
in
thickness by successive
division
of
its
ascending
filaments,
but
in
the group
of
P.
(Cruoriella) polystrata we
find
a
thick frond
consisting of layers
of nar-
row
fronds
lying one above the
other,
creeping
continually
over
each
other
and forming a thick frond by this mode
of growing. Again in another species the
frond,
after
having acquired
a certain
thickness, splits or tears
in a horizontal
direction
;
the
lower part decays
little
by little, the upper part continues the growth of the frond
;
its
in-
ferior cells grow larger, produce rhizines and develop the characters
of an ordinary hypothallus.
Such a young thallus, after having ac-
quired the necessary thickness, will
split
in
its turn
;
I have seen
Fig. 139.
Cruoriella armo-
rica. Crn.
Filaments of the
hypothallus
forming
little
fanshaped groups.
(90
: 1).
331
two and three remnants of old thalli underlying a young one.
It is
curious
that
the
old
thalli
decay
in
this
species, whereas
in P.
(C.) dura
-
- the type
of
HEYDRICH'S
Polystrata
-
-
all
the
thalli
are
preserved.
This
depends,
as
I
believe, on
the
fact that P.
(C.) dura has a calcareous
frond and that P. (C.) Nordstedtii, as
we
will
presently
see,
is
mostly
of
soft texture with only
little
calcareous matter distributed throughout the
frond.
The anatomical structure
of the Peyssonnelise
is much
alike;
it
consists,
as we know,
of creeping filaments -
the hypothallus
- and
each
cell
of
these
filaments
gives
off,
seen
on
longitu-
dinal
sections,
an
obliquely
ascending
filament,
these
constitute
the
perithallus.
The
cells of the
perithallus
differ
in
heigth and
breadth
in
different
species, but
still
these characters
are to be
used very
carefully,
for the size of the cells will vary
in the same
specimen
according
to
the
spot where
the
section
is made and
according
to
the
age
of
the
plants.
On
the other
hand, when
studying many
species
of
this
genus, we
find
different
species
with
cells
of
almost
the
same
size.
Searching
for
a
character
that might help
to
distinguish the puzzling
species,
I was struck
with
the
fact that the
topcell
or
apical
cell
divided
differently
in some
species,
though these
divisions
corresponded
essentially
with the
divisions
of P. (Eup.) squamaria.
The
anatomical
structure
of
this
alga
has been,
as we
well
know, the
object
of careful research by NAEGELi 1
), who has also
given good
figures to show, how the
filaments of the hypothallus,
seen from
above, divide dichotomously to increase
their number,
according to the fan-shaped growth
of the
frond.
The
longitudinal growth
of the filament that
interests us
for
the
present, depends
upon the
partition, of the
apical
cell by a
more
or
less
oblique
membrane
on
its
longitudinal
axis.
In
P. (Eup.)
squamaria
and
-
as
far
as
1
can
judge
-
in
most
species,
this
apical
cell
is
relatively
high
(in
vertical
direction)
and
horizontally
short.
After
division,
the
outermost
segment
grows
on,
until
it
has reached
its former
size
and
then
divides
again.
The
inner segment
increases
also
in
size,
it may divide
again by a
vertical
cellwall, though
this
is rarely the
case
;
as a
rule
it
divides,
after having
attained
a
given
size, by
a
hori-
zontal wall into two unequal portions of which the uppermost
is
destined
to become the mothercell
of the ascending filament and
the
inferior constitutes part
of the hypothallus.
This
inferior cell
may be
less high than the superior one
(P. (Eup.) squamaria) or
1
) NAEGELI, Die neueren Algensysteme, 1847,
p. 248.
9*
132
Fig. 140.
Peyssonnelia (Cru-
oriella) simulans
nov. spec.
Section
throug
the.' margin
of thallus.
t. topcell or apical
cell
; the one row of inferior
cells constitute the hypothal-
lus, the ascending, still short
cellrows, the perithallus.
(200:1).
it may be higher (P. (Eup.) simulans), but
it
is always
less high
than the
apical
cell
(Fig. 140).
In a few other species (P. (Eup.) rubra} the topcell or the cells
following may be longer than high
;
it divides
just
like the short
one by an oblique cellwall on its longitu-
dinal axis into two segments. The outer
one grows until
it has reached
its
for-
mer size and then divides again. The in-
ner segment will grow too, and may first
divide again by a vertical cellwall
; if this
is the case, the third or even the fourth
cell after repeated division, increases in
height
and
then
divides
by
a
hori-
zontal
wall
into
two
often
unequal
portions.
The
inferior one retains the
height
it had
at the moment
of
divi-
sion
of
the
apical
cell
;
it
communicates
with
its
neighbouring
hypothallic
cells
of the
same
filament
through the primary cen-
tral pore
; the upper portion
is the mother
cell
of the ascending
filaments.
I thought
at
first that
these
differences
in
growth
of
the
apical
cell
might
coincide
with the
branching
of the hypo-
thallus, but
this
is
not
the
case.
I have found the
short, high
apical
cell
in
species belonging to the subgenus Eiipeyssonnelia as
well
as
to
the
subgenus
Cruoriella
and
in
both
subgenera
the
longer
and
less
high
apical
cell.
Therefore
I consider this character
only useful
as a specific one, but
as a good one, for great as the va-
riability
of the Peyssonnelia may
be,
I can not imagine that a top-
cell
as
in
Fig. 140 can grow into
a
topcell
like
Fig. 144.
When
treating
of the Peys-
sonnelia of the Siboga Expedition,
I
hope
to
be
able to give
some
more
details
about
the
growth
of the
apical
part
of these
alga3, but this study
is very tedious,
for dried
specimens
have
the
margin
often crumpled
or broken
off.
It
is
also
difficult
to get good
longitudinal
sections and the
topcell must
be
in
a growing
stage.
In
old
fronds, when
their
maximum
size
is reached, the topcells cease growing
in
radial
di-
rection but they may still
divide
in another way and
slides made
- rr
Fig 141. Peyssonnelia rubra (Grev.)
J.
Ag.
A
longitudinal
section
through margin of thailus.
t. top-
cell
;
p.
perithallus;
/?. hvpothal-
lus;
rh.
rhizoid.
(360:1).
133
unfortunately
through
a
thallus
in
such
a
state,
will
only add
to the
confusion. x
)
The
fruit
of
the
Peyssonnelia
are
nemathecia
with
carpo-
spores
and
tetraspores
raised
above
the
surface
of
the
frond.
By
these
nemathecia
the
Squamariacese
are
easily known
from
the
Melobesiacese
which
they
resemble
so
much
in
anatomical
structure.
SCHMITZ*)
described
the
development
of the
procarp
and
the
auxiliary
cells
in Peyssonnelia
but
he
gave
no
figures
and
it
is
highly desirable
that
his investigations should
be
re-
peated.
It
is, however, very
difficult
to
obtain
good
material.
The
collection
of
Dr. B0RGESEN
contains
only
nemathecia
with
carpospores and tetraspores.
But
nemathecia
with
ripe
carpo-
or
tetraspores
are
also a
character
of importance when describing new
species.
While stu-
dying
the
Siboga
material
I
had
ample occassion to appreciate
their
value,
but
the
specimens
collected
by
Dr. BORGESEN
are
more uniform
in
this
respect than the East-Indian
species.
The collection of
Dr. B0RGESEN
is
rich
in Peyssonnelia.
MAZE
et SCHRAMM
in
their "Les Algues de
la Guadeloupe" mention only
Peyssonnelia Dubyi
and
MURRAY
in
his
"Catalogue
of
marine
algffi of the West-Indian region" knows of no other representative
of
this
family.
It
is
therefore
not strange that
Dr. BORGESEN'S
collection
contains
many
novelties
but,
alas,
also
some
plants
about
which
I
feel
uncertain.
These
alga9
resemble well-known
species
but
are
not exactly
like
the type-specimens
;
if now the
J
) Continuing my
research
on
the
apical
cell
of
the
Peyssonnelia
after
having
finished
this
paper,
I observed
a stage
of rest
in
the thallus
of P. rubra, followed by a period
of intense growth. A section through
the
margin
in
a
state
of
rest, gave a figure
resembling the
figure of
P. Boergesenii
(Fig. 144).
On
this period
of rest followed a
period
of
growth
in
which
the
topcell
and
the
cells immediately following
it,
wore different aspects
in succeeding longitudinal sections.
I think that
these succeeding stages of growth
and
rest correspond with
the con-
centric
lines and
smooth zones we observe
in
the thallus of P. rubra
that has,
as we know, a turned
up margin.
The spot from where the
new
growth
begins,
is
attached by
rhizoids
to
the
substratum;
the
young
frond
curves
distinctly upwards
but by
succeeding growth
it
stretches
itself
horizontally
and
will
afterwards
attach
itself
to
the
substratum.
I suppose that the concentric lines on the thallus coincide
with
the
spot
from where the new growth begins, and which carries
many
rhizoids.
The
intervening
zones
between two
concentric
lines
have as a rule far lesser rhizoids.
2
) SCHMITZ,
Untersuchungen
iiber
die
Fruchtbildung
der
Squamarieen,
Sitzungsber. d. niederrh. Gesell. Bonn,
1879,
p. 376.
134
material
was
scanty
or
the
specimen
sterile,
I
queried
these
doubtful
specimens
and
placed them
near to
the
species which
they most
resemble, leaving
it
to
future
investigators to decide
whether they are forms
of the type
-
-
or new
species.
One specimen belongs probably to the genus Cruoriopsis, but
it
is
in such
incomplete
state, that
it cannot
be
identified with
certainty.
Besides the
easily known and doubtful
species the collection
of Dr. B0RGESEN
contains:
two new
Cruoriella,
one new Peyssotmelia and
one new
Contarinia,
of the family
of the
Rhizophyllidacese.
Before giving
the systematic
list
of
the
species,
1 may per-
haps add
a few words to express my sincere thanks
to
Dr. BOR-
GESEN,
for entrusting me with
his
collection and
to
Mr. HARIOT
of
the Museum
d'Histoire
Naturelle de
Paris,
for
his kind
help
in sending me valuable specimens
for comparison.
Cruoriopsis Dufour.
1.
Cruoriopsis
spec.
One of the small specimens
in the collection of
Dr. BORGESEN
carries
at
the
top
of
the
ascending
filaments two
short
files
of
moniliform
cells
of
peculiar aspect; they remind one
of the
car-
pospores
in the cystocarps
of Cruoriopsis cruciata.
The
cells
are,
however,
still
very young and
I
have seen
no
other
organs
of
fructification.
I
do
not
dare to name
this
alga with
certainty
but
I
think
it
likely, that
it
is
a member
of
the genus Cruo-
riopsis.
Found
at St. Thomas,
in the harbour at the French Wharf.
(N. 52).
Dry Specimen.
Peyssonnelia Dec.
Key to the subgenera and
species
of Peyssonnelia from the
West-Indian
region,
collected by
Dr. F. BORGESEN.
I.
Thallus
procumbent, more
or
less
firmly adhering to
the substratum,
orbicular or
irregular in
outline, with
a hypothallus consisting of dichotomous filaments, run-
ning from the centre towards the periphery and form-
135
ing small, lanceolate, fan -shaped groups.
From
the cells
of the hypothallus
rise more or
less obliquely
ascending filaments: the
perithallus.
.
. Subgenus Cmoriella.
a.
Thallus
hard,
calcareous,
firmly
adhering
to
the
substratum.
1.
Thallus
very
thin,
when
decalcified
easily
de-
tached from substratum and so small that it can
be expanded in toto on a slide
; colour dark pink.
P. armorica Grn.
2.
Thallus
much
firmer,
surface
slightly
marked
with small low elevations, sometimes with radial
lines but no veins
;
perithallus with an
inferior
part
of
large
cells and
a
distinct superior part
with small
cells
;
colour dark pink
.
.
.
P. Dubiji Grn.
3.
Thallus very
firm,
surface smooth but with
di-
stinct
veins
running
from
the
centre
towards
the periphery
; perithallus with cells often almost
isodiametric except the basal large and the su-
perior
small
ones.
Colour
dark
purple with a
green hue
P. Boergesenii nov. spec.
b.
Thallus
fleshy,
slightly calcareous
at
base,
firmly
adhering
to
substratum and tearing
in
horizontal
direction
after having acquired
a given
thickness.
Inferior cells
of the upper, torn
off, part transform
into a new hypothallus
;
colour probably pink
.
.
.
P. Nordstedtii nov. sp.
II.
Thallus
procumbent, adhering more
or
less firmly to
the substratum,
orbicular
or irregular in
outline, with
a
hypothallus
consisting
of
in
the main
straight,
juxtapposed, dichotomous
filaments,
running
from the centre towards the periphery,
giving
rise
to
more
or
less
obliquely ascending
filaments
: the
peri-
thallus
Subgenus Eupeyssonnelia.
a.
Thallus
hard,
calcareous, with
short,
high
apical
cell.
1.
Thallus
thin,
consisting
of
6,
7
layers
of
cells,
easily
detached
from
substratum,
mostly
orbi-
cular with
radial
lines
;
colour
light pink ....
P. simulans nov. sp.
2.
Thallus
more
robust,
firmly
adhering
to
the
substratum,
colour
purple
P.
conchicola
Pice,
et Grun.
136
3.
Thallus very firm, easily loosened from the sub-
stratum,
irregular
in form ;
perithallus with
in-
ferior
part
of
large
cells,
superior
part
with
smaller
cells; colour brick red
P. polymorpha (Zan.) Schm.
b.
Thallus membranaceous-calcareous with long apical
cell as high as hypothallic
cells, orbicular with slight
radial lines and concentric zones; colour pink or
red.
P. rubra.
Subgenus
1.
Cruoriella Cm.
1.
Peyssonnelia
(Cruoriella) armorica (Cm.).
Cruoriella armorica Crouan
in Ann. Sc. Nat., 1859,
4e serie.
t. 12;
Flor.
du
Finist.
1867,
p. 148,
tab.
19,
fig.
128.
DE TOM,
Syll. Alg. vol. IV,
1905,
p. 1691.
This small alga was detected growing on other Peyssonnelia.
Thanks
to the extreme kindness
of M. HARIOT,
assistant au Mu-
seum
d'Histoire
Naturelle
at
Paris,
I was able to compare
it
to
an
authentic specimen
of CROUAN.
The comparison showed
the
absolute identity
of the two specimens.
Found
at
St. Thomas
in
the sea
to the west of Water Island
in a
depth
of about 15 fathoms.
In
alcohol.
(No. lllOni).
Geogr. Distrib.: Atlantic coast
of Europe, Mediterranean Sea.
2.
Peyssonnelia
(Cnioriella) Dubyi Crn.
CROUAN,
Ann. d. Sc. Nat.
1844,
p. 368,
tab. 11.
SCHMITZ,
Uebers. der
Florideen,
1889.
p. 20.
DE TONI,
Syll. Alg.
vol. IV,
sect. IV,
1905,
p. 1691.
Peyssonnelia Dubyi belongs to the subgenus Cruoriella because
its hypothallus
consists
of
fan-shaped
little
groups
of
filaments.
These filaments have
in
horizontal
direction a
short and
in ver-
tical
direction
a
high
apical
cell,
higher than
the
cells
in
the
hypothallic
filaments.
P. Dubyi was
the
only known
Squamariacea
of
the West-
Indian region before
Dr. BORGESEN'S Expedition.
Found
at
St. Thomas
in the sea
to the west
of Water Island
in a
depth
of 15 fathoms.
(N. 1030).
Dry specimen.
Geogr. Distrib.:
Atlantic coast
of Europe.
137
3.
Peyssonnelia
(Cruorielja)
Boergesenii nov.
spec.
Thallus
totus
adnatus,
valde
calcarius,
superficie
levi cum
singulis
venis
conspicuis,
e
centro
ad
peripheriam
currentibus,
constans hypothallo
et
perithallo.
Hypothallus constat
filamentis
repentibus,
juxtappositis,
flabella
angusta,
elongata,
efficientibus.
Cellula
apicalis longa;
cellulae filamentorum hypothalli seque
altse
aut
altiores
ac
cellule
apicales.
In speciminis
juvenilibus omnes
cellulse filamentorum repen-
tium
fere
eequales, in speciminis adultioribus axis
principalis con-
spicuus,
cellulis majoribus.
Perithallus
divisus
in
partem
inferiorem,
cellulis
magnis,
tetragonis aut
l l
/z
altioribus quam
latis,
altis 40
36 //, latis 40
36
20^ et
in partem superiorem, cellulis gradatim decrescentibus.
Cellulis
periphericis
multo
brevi-
oribus
quam
latis,
altis
10
/^,
latis
20/u.
Nemathecia cum carposporis
quadripartitis zonatis, paraphyses
cellulis longioribus quam latis, altis
40361612
fji,
latis 68-
12^
et
cellulis apicalibus monili-
formibus.
Nemathecia cum tetra-
sporangiis
ignota.
Thallus
altus
rh 500 p, nemathecia 240 //.
Peyssonnelia (Cruoriella) Boer-
gesenii
1
}
(Fig.
142)
distinguishes
itself by
its
smooth
surface marked
with
delicate
but
distinct
veins,
visible
to the naked
eye and
running
in a fan-shaped
di-
rection from the
centre towards the
periphery.
These veins
are
quite
different from the
radial
lines, we observe
f.
i. in the
thal-
lus
of P. rubra and depend
probably upon
the
axis
with
large
cells
of the hypothallus.
In
a dried
state the colour
of the
thal-
lus
is very striking owing to the greenish hue of the dark purple
frond.
In
the
collection
of
Dr. BORGESEN
are
four numbers
from
the
same
locality
that
I
believe
belong
to
this
species, though
in
structure
they show some
differences,
but
these
differences
depend on the age of the
individuals.
Seen from below No. 1442
Fig.
142.
Peysonnelia Boergesenii
nov.
spec.
Surface
view
of
the
plant.
X 1,6.
I
have great
pleasure
in
dedicating
this
alga
to
Dr. BORGESEN, the
botanist and explorer
of the
marine
flora of the
Danish West-Indies.
138
has a hypothallus with
cells
of the same
size, whereas No. 1546
11
seen
from
below, has a
hypothallus
with
cells
of
different
size
constituting
a
principal
axis
of
larger
cells
from which
spring
files
of
smaller
cells, that
form
together
groups,
like
elongated
little
fans.
The
frond
of
No. 154611
is
rather thick,
it must
be an
old
plant and
I think that by succeeding growth, changes
in the basal
layer
of the frond have taken
place.
Only too
often, when
stu-
dying
Peyssonnelia ,
one
sees
that
the
basal
layer
undergoes
changes, and
these can ultimately tend
to the solution and even
disappearance
of
part
of
the hypothallus.
In P. Boergesenii the
Fig.' 143.
Peyssonnelia Boergesenii nov. spec.
View of two
hypothalli,
loo-
sened from the substratum,
a. (No. 1442) young hypothallus. "principal axis
not yet
differentiated,
b. old hypothallus with
distinct principal
axis.
(No.
1546 ii).
(210:1).
hypothallus
is not soluted
; the cells of the principal
axis
increase
simply
in
size.
The apical
cells
is long and
as high
as or
less high than the
cells
of the basal layer
(Fig. 144)
l
) and
in
this
respect P. Boerge-
senii
differs from P. Nordstedlii that has a high, short
apical
cell,
like
Fig. 140.
The perithallus
(Fig. 145)
consists
of a Jower part
of almost
square
cells, high d=40^, on which
follows
an
upper
part with
The
section
after which
this
figure was
made, did
not quite
satisfy
me;
I
fear that
it
is a section throng a margin
no longer in a grow-
ing
state,
but
I could
get
no
better
for the margin
of the alga was
very much
broken
off.
This section
shows, however, that the
apical
cell
is not a high, short
one.
139
Fig.
144.
Peyssonnelia Boergesenii nov.
spec.
Section through dried margin of
thallus.
t.
topcell.
(380
: 1).
cells higher than broad,
di-
minishing regularly towards
the periphery, the peripheral
ones
being
the
shortest
of
all: height 10^, breadth 20 a.
This succession
is, however,
not
always
so
striking
as
told
here.
The
frond
can
easily
attain a
thickness
of 500 //,
even
more,
for my sections
do
not
run
through
the
thickest
part
of the
frond.
The cells contain much gra-
nules, that take at first a golden brown colour by hydrochloric zink-
iodine and become almost black under long influence of the reagens.
I have only seen
one nemathecium with
carpospores.
It
had
a darker colour than
the
frond,
was
ele-
vated
above
its
sur-
face and
irregular in
form
;
it had a height
of 240
(JL and the qua-
dripartite, zonate car-
pospores of IQQfjt, but
these looked as if they
were
not
yet
quite
ripe.
The paraphyses
ended in a short, round
cell,
not
in
a
broad
blunt one (Fig. 145, a).
Nemathecia with
antheridia were more
frequent
;
I
found
them
on
the
same
plant
as
the
carpo-
spores
(Fig. 145 c).
This Peyssonnelia
resembles
P. Harvey-
ana very much with
Fig.
145.
Peyssonnelia
Boergesenii
nov.
spec.
a.
section
through
nemathecium
with
carpo-
spores
;
b.
section through thallus in transverse
direction;
the inferior cells are sometimes larger
when
the section
hits upon
a principal
axis
of
the hypothallus
; when
the section
is made
in
longitudinal
direction
the inferior
cells
ascend
obliquely.
(250
: 1).
c. section through nemathe-
cium with antheridia.
(540:1).
140
regard to its anatomical structure, but it differs from this alga by its
hypothallic
filaments, running in
little flabelliform groups over the
substratum; the colour of both alga3 is also different, P. Boergesenii
being of a dark purple colour with a greenish hue over it, P. Harvey-
ana of a bright red colour.
Lastly P. Boergesenii
is also character-
ized by the
distinct veins running
from
the
centre towards
the
periphery.
Found
in
shallow
water,
St.
Croix, White
Bay.
(N. 1537 n, 1546 n,
1585 ii).
Rust
of Twist (N. 1442).
In alcohol and dry specimens.
4.
Peyssonnelia
(Cruoriella)
Nordstedtii nov. spec.
Thallus tota
superficie
inferiore
adhaerens, paulum
calcarius,
colore
ignota, diametro usque ad
4 centimetrum, constans hypo-
thallo
et
perithallo.
Hypothallus constat
filis
repentibus, juxtap-
positis, parva
flabella
efficientibus.
Cellula
apicalis
filorum
alta
et
brevis,
in
sectione longitudinali
altior
filis
hypothalli.
Cellule long* 28
36
40 p, latse 16
20
28
,
et
28 // altse.
Perithallus constat
filis adscendentibus, stratum satis crassum,
denique fissum formantibus.
Pars
inferior hujus strati
perit, pars
superior hypothallum novum
efficit, cum radiculus
uni-
et
pluri-
cellularibus partem inferiorem tegente,
radiculis
iis
in partem
in-
feriorem penetrantibus.
Cellulse altse
122036 u, latse 121620^.
Nemathecia
cum
tetrasporis
quadripartitis,
cruciatis, tantum immatura
visa.
Peyssonnelia (Cruoriella) Nordstedtii 1
) resembles an
alga
col-
lected
at the
island
of
Nias, Sumatra^ that
I have
called
in my
manuscript
of the Siboga-algse, later on
to be published, P. Nord-
stedtii.
Both
algse have
in common
a frond
of soft texture, only
slightly incrustated with carbonate
of lime and the peculiar way
of renovating the
frond.
P. Nordstedtii belongs to the subgenus Cruoriella on account of
its hypothallus consisting of filaments branching by repeated dicho-
tomy, which branches grow until other filaments, crossing their way,
stop
their growth.
The branching filaments form
little elongated
fan-shaped
groups,
springing
from
a
principal
axis
with
larger
cells
than the
cells
in
the fan-shaped groups,
just
like what we
have seen
in P. Boergesenii (Fig.
143).
Characteristic of P. Nordstedtii
is the way
in which the
peri-
1
) Named
in honour of and
in gratitude to Prof. O. NORDSTEDT at Lund,
the learned
algologist,
to whom
I owe so many graceful
acts of kind-
ness.
141
thallus may tear
horizontally
after having acquired a
thickness
of
11
cells
or more.
The
inferior
4
5
cells
are the
largest, the
cells
higher up
are smaller
in diameter, and the peripheral
cells
are the
shortest
of
all.
Between
the
inferior
large
cells
and
the
succeeding
ones,
which are somewhat
smaller, the membrane thickens.
This thicke-
ning
of
the membrane
takes
place
in
horizontal
direction,
and
may
spread
over
some
distance.
In
this
thick
membrane
ap-
pears
at
first a slight opening,
this
enlarges, tears the membrane
horizontally and divides the perithallus into a superior and
inferior
part; these can remain jointed but very often they tear asunder.
Fig.
146.
Peyssonnelia
Nordstedtii
nov.
spec.
Section
through
thallus
in
transverse direction
in the moment
that
the
upper
part
tears
itself
from
the partially decaying inferior part.
(210
: 1).
In
either case the
upper
part
will
increase
in
thickness and
its
inferior
cells increase
in
size, and
then the membrane
will again
thicken
at
the
same
place
as
formerly,
above
the
four or
five
layers
of
large
cells.
If the
perithallus
is not
torn, we
see the
succeeding layers forming one continuous mass.
But
often the
perithallus
splits
into two
layers;
if
this hap-
pens we observe
first a
little opening in the thickened membrane,
this
enlarges quickly and
divides the
perithallus
into two
parts
(Fig. 146).
The upper part transforms
its basal
cells, that were formerly
in the middle of the ascending filament, into a young hypothallus,
with uni- and
pluricellular rhizines that penetrate
in the
inferior
part
of the
perithallus.
142
The cells of this
inferior part are
filled with grams of starch,
yet they
will
die
or dissolve
little by
little;
it may also be that
the
rhizines get some nourishment out
of them.
In
sections
I have often seen three
layers of
thalli one above
another.
By these superposed
thalli P. Nordstedtii approaches the
group
of P. polystrata
of which
P. dura Heydr.
is the type.
The
name
dura, given on account
of the hard
calcified nature
of the
frond, is alone
sufficient to show that our alga with
its soft
frond,
is a different
species,
not
to speak
of
other
differences,
afforded
by the peculiar structure
of the nemathecium
of P. dura.
I
have
seen
only
one
nemathecium
of
P.
Nordstedtii with
cruciate
tetraspores, but
it was
still
unripe.
It had a height
of
80//, and the paraphyses ended with a blunt
cell; the
cells were
I l
f2
2
as
long
as
broad
but
this
will
change with succeed-
ing growth.
P. Nordstedtii ad-
heres
totally
and
firmly
to
the
sub-
stratum.
I
cannot
say
anything about
its colour
for
it was
preserved
in alcohol
and
1 have seen no
dry specimens from
the W. Indies.
The specimen from Nias that has
so much
in common with
the W. Indian
one, has
a pale pink
colour.
Found
at St. Jan
off Cruz Bay
in a depth of about 12 fathoms.
In
alcohol.
(No. 1903).
Subgenus
2. Eupeyssonnelia.
5.
Peyssonnelia
(Eupeyssonnelia)
simulans nov. spec.
Thallus
tenuis,
orbicularis aut
irregularis,
substrate tomento
brevi
adhserens
sed
facile
a
substrate
solutus,
durus,
calcarius,
zonas concentricas
et lineas
radiales vix conspicuas
exhibens, con-
stans hypothallo
et
perithallo.
Hypothallus constat
filis
rectis,
juxtappositis,
cellula
apicali
brevi,
lata
instructis.
Cellula apicalis
in sectione radiali altior
filis
hypothalli.
3QQDQQQ
GOOQGEL
Fig. 147.
Peyssonnelia Nordstedtii nov. spec.
Sec-
tion through part of nemathecium with cruciate
tetraspores.
(250
: 1).
143
Cellulse
longse
20
28
32
40//,
latse 1620^,
in
sectione
alt ee 2024^.
Perithalli
cellules
infimse
omnes
fere
seque
altas
ac
cellula?
hypothalli
; in, sectione transversali
altiores quam
Iata3,
in
sectione
longitudinali
fere
quadratic*,
cellula?
superiores
gradatim
de-
crescentes.
Celluke
altae 2428^,
latae 20^.
Nemathecia
in
thallo parvas maculas obscuras irregulares
ef-
ficiunt,
carposporis
tripartitis
zonatis
et
paraphysibus
obtusatis
quorum
cellulse 1V2
altiores sunt quam
latae.
Nemathecia
alta 200 ^.
CarposporaB 100 //.
Nemathecia cum
tetrasporangiis, cruciatim
divisis.
Tetrasporaa
altaa 60
80 /^.
Peyssonnelia simulans has
received
its name
because
it
has
so many points
in common with P. conchicola that
I
felt doubtful,
whether
it might
not
be a form
of P. conchicola but
it can not
be
identified with
this
alga and
therefore
I
prefer to
describe
it
as a new
species.
P. simulans distinguishes
itself from P. conchicola by adhering
loosely to the substratum;
the
collection
of
Dr. BORGESEN
con-
tains
entire
loosened
specimens,
whereas
P.
conchicola
adheres
firmly to the substratum.
The colour
is
different
in
both
algaa,
P. simulans being
of a bright
pink colour
not
red
- and P.
conchicola
of a red
colour
that
fades
partially away
in
drying.
The faded
parts have a yellowish pink
colour.
It
is
true
that
as
a
rule
colour
is
a bad
characteristic of
algee
but
in
the Peyssonnelia
it
is
such a marked
feature, that
it probably can be
of great help in knowing the different species.
P. simulans
resembles
P. conchicola by
its
hypothallus
con-
sisting of straight-running filaments ending in a short, high
apical
cell, which
is
higher
than
the
filaments
are
at a
little
distance
from the top.
Its
perithallus
is characterized by an almost square
lower
cell, that
divides
at
its top,
seen
in
longitudinal
section,
in two rows
of
cells
(Fig. 140).
This
is often the case
in
species
of Peyssonnelia
but
seldom
so
regularly and
in
such
a marked
way as
in
this
species.
Under
slight pressure on
the cover
slip,
the
cellrows loosen
in
vertical
direction
after decalcification and
this
I have never observed
in
sections
of P. conchicola.
I
could
study this alga thoroughly thanks to the kindness of
Dr. A. FORTI,
who send me an authentic specimen
of
Dr. PICCONE
for compari-
son.
I may well thank him here
for his kindness.
The
thallus
of P. simulans
is
incrustated with
carbonate
of
lime;
it
is
thin, the thickest thallus
in
Dr. BORGESEN'S collection
144
has no more than
five or six layers of
cells and
thalli with three
layers
of
cells
carried even nemathecia with
tetraspores.
A spe-
cimen (No. 1110
11
) preserved
in
alcohol,
carried nemathecia with
tripartite, zonate carpospores
(Fig. 148); one
layer
of
cells under
the
nemathecia was exceptionally
high
in
another plant.
Some
plants
have a thick
basal
layer
of mucuous substance, but
this
character
is not
constant.
To sum up the
differences
between P. simulans
and
conchi-
cola we
find
that P. simulans has a
lighter colour, does not ad-
here
to the substratum
and
that
it
must carry more carbonate
of lime
in
its tissue for,
after
decalcification, the
cells
loosen
easily from
each
other
in
vertical
direction.
The contents
of
the
older
cells,
con-
sisting
principally
of
grains
of
starch
in
P.
simulans
are more
ho-
mogenous
in
P.
conchi-
cola.
For
all these
rea-
sons
I
am,
I
believe,
authorized
to
describe
the
present
alga
as
a
new
species.
Fig.
148.
Peyssonnelia
simulans
nov.
spec.
Cross section through thallus with nemathe-
cium
with
carpospores.
b.
basal
layer
of
mucuous substance.
(000
: 1).
"
This species was found
at St. Thomas in the sea
^^^^^^
to the west of Water Island
in
a depth of about
15
fa-
thoms (No. HIGH), St. Jan
off
St. Cruz Bay
in
depths
of .about 10-15
fathoms
(No. 1916, 1752,
1828),
off Ram's Head
at
depth
of about 25
fa-
t horns (No. 1943).
In alcohol and dry specimens.
6.
Peyssonnelia
(Eupeyssonnelia)
conchicola
Pice, et Grun.(?)
PICCONE
et GRUNOW
in PICCONE, Algae
eritrea, 1884,
p. 317.
DE TONI,
Syll. Alg.,
vol. IV,
sect. IV.
1900,
p. 1700.
The
alga3 from the West- Indies that
I
call P. conchicola, ad-
here firmlv to the substratum and
resemble
in anatomical char-
f
acter
the
type specimen
from
the
Red
Sea.
The West
Indian
ones carry nemathecia with
tetraspores, nemathecia with
carpo-
spores
I
have
never
seen.
P. conchicola
has
been
described by
GRUNOW and
PICCONE
after
barren
specimens;
it may therefore
145
be
possible
that,
if
fertile specimens
are
found, the West-Indian
plant
will prove to be a
different
species.
I
queried
it therefore
and
also, because
its colour
is darker than
the colour
of P. con-
chicola.
It
resembles,
as
already stated,
P. conchicola
in
anato-
mical structure and
differs
from
P. simulans,
in
adhering
firmly
to the substratum.
From P. rubra
it
is
easily known by
its long
apical
cell.
Found at St. Croix, White Bay,
in shallow water (No. 15371, 15461,
1585 T
).
In alcohol and dry specimens.
Geogr. Distrib.:
Red Sea.
7.
Peyssonnelia (Eupeyssonnelia)
polymorpha?
(Zan.) Schm.
SCHMITZ, in Falkenb.,Alg. Neap., 1879,
p. 264.
DE
TONI,
Syll. Alg.,
vol. IV,
sect.
IV,
1905.
p. 1701.
Lithymenia polymorpha Zanard., Icon.
Phyc, Adriat.
I,
1860,
p. 127,
tab. 30.
The
specimen
No. 1966
belongs
probably to
P. polymorpha, but
it
is
too
small to name
it with
certainty.
V
It was
collected with the dredge and
we know
that P. polymorpha prefers
deeper water. Mme LEMOINE l
) has de-
scribed
this alga from various
locali-
ties
in the Mediterranean, and a va-
riety
of
it
has
also
been
found
at
the
island
of Amirante 2
)
The
speci-
men from
St. Thomas
has
the
typical
brick-red colour
of
the
species, the
hollow crust
is
entirely
loosened
from
the
substra-
tum and
the
anatomical
structure
is
very
much
like
that
of
P.
polymorpha.
The
specimen
bore
nemathecia
with
unripe
carpospores.
Found
at St. Thomas
near
the West-End
of
the island
off Thatch
Bay
in a depth of about 14- 16 fathoms (No. 1966).
Dry specimen (by Dr.
TH. MORTENSEN).
Geogr. Distrib.: Mediterranean Sea.
toroto
Fig.
149.
Peyssonnelia
con-
chicola Pice, et Grun.
Cross-
section
through
nemathecia
with tetraspores.
(260
: 1).
1) Mme p. LEMOINE et M. MOURET, Sur une algue nouvelle pour la France.
Bull. Soc. Bot. 1912,
p. 356.
2
) A. WEBER-VAN
BOSSE,
Rhodophycese
of
the
"Sealark"
Exp.
Trans.
Linn. Soc. 1913,
p. 139.
10
146
8.
Peyssonnelia
(Eupeyssonnclia)
rubra
(Grev.)
J. Ag.
J. AGARDH,
Spec. Alg.
II,
1851,
p. 502,
Epicr.
Flor. 1876,
p. 386.
DE
TONI,
Syll. Alg. vol. IV,
sect. IV,
1905,
p. 1696.
Zonaria rubra, GREVILLE
in Linnean Transact. XV,
prt.
2,
p. 340.
After some
hesitation
I
have named
two specimens
in
Dr.
BORGESEN'S
collection
as P.
rubra,
though ScHMixz 1
)
doubted
of
the occurrence of P. rubra
in a tropical sea and though, according
to
J. AGARDH, P. rubra
should
be
limited
to the Mediterranean.
J. AGARDH describes the frond
of P. rubra as "membranacea" but
the carbonate of lime incrustated between the rhizoids and
in the
basal mucuous layer makes the plant very brittle and calcareous.
I
could
detect
no
difference
between
specimens
from
Naples,
Genoa, Antibes and those from the West Indies.
The
latter are
perhaps a
little more
delicate
and
orbicular,
not
so
profoundly
lobed
as the Mediterranean
species can
be.
Found
at St. Croix, White Bay, shallow water,
(No. 1546 n, 1585 n).
Dry specimens.
Another specimen
(No. 2034) found
at St. Jan,
off America
Hill
in
a depth of about 15 fathoms,
is distinguished by its
light, pink colour and
thin
thallus
from P.
rubra.
Its
ascending
filaments, seen
in
longitudinal
direction, run more obliquely and
the
first
cell
of the perithallus
is higher
than
is usually the case in P. rubra.
This alga stands between
P. rubra
J.
Ag. and
P. Gunniana
J. Ag.
I
hope
that
future
explorers
of
the West-
Indian region, with more material at their disposition, will shed further light
on
the systematic
position
of these confusing membranaceous species and
will
settle my
doubts
about
P. simulans, whether
it
is a new
species
or
to
be
sunk
in
P.
conchicola.
I
felt,
while
working
out
this
collection,
that
to know the limits of a species, one must
first distinguish,
in order to
be
able
to
unite afterwards and
that
for the
present
I
could
only
distin-
guish and had no right to unite.
Fam.
4.
Hildenbrandiacece.
Hildenbrandia 2
) Nardo.
1.
Hildenbrandia prototypus Nardo.
S
T ARDO,
I.,
in
Isis,
1834,
p.
675
(Hildbrandtia).
HAUCK,
F.,
Meeres-
algen,
p.
38.
*) SCHMITZ,
Marine
Florideen von
Deutsch
Ost-Afrika,
ENGLER'S
bot.
Jahrb.,
1895,
p. 172.
2
) Regarding the spelling of
the generic name compare the foot note
in
ENGLER
u. PRANTL.,
Die
Naturl.
Pflanzenfamilien
,
I.
Teil,
Abt.
2,
p.
644.
147
Hildenbrandia Nardi Zanardini,
Synopsis Algarum
in
Mari
Adriatico
hucusque collectarum (Acad. Re delle
Sc.
di Torino,
Cl. mat.
e
fis.,
2
ser.,
t. IV,
p. 238,
tab. 1,
fig.
1).
J. AGARDH, Spec.
Alg.,
II,
p. 494,
III,
p. 379.
Hildenbrandtia
sanguined
Kiitz.,
Phycologia
generalis,
1843,
p.
384,
tab.
78,
V.
This
alga
has
been
found
in
shallow water
near
the shore
covering stones and
pieces
of rocks.
I have compared my
plants with European
specimens from
various places and they seem to agree quite well with these.
The
cells
in the
vertical rows of
cells
in the thallus
are about
4
5/*
broad.
HAUCK
1.
c.
says that they are 4^.
The irregularly
shaped tetrasporangia
are cruciately divided
but
often
the walls
are
placed
rather
anomalously.
The
tetra-
sporangia are about
25 /* long and
13
fj. broad.
This plant occurred
in more sheltered
places.
As
I previously
have mentioned *)
its thin purple-reddish crusts were found upon
stones
in a lagoon
at St. Groix growing in the shade of the man-
grove
trees;
at
St. Jan
it was growing upon small round stones
in a more open
place.
St. Croix:
Saltriver Lagoon.
St. Jan:
Cruz Bay.
Geogr.
Distrib.
:
Jamaica,
Brazil,
Atlantic
Ocean,
Mediterranean
Sea,
Pacific Ocean
etc. most probably ubiquitous.
Fam.
5.
Corallinacece.
Subfam.
1.
Melobesieae.
Par M me PAUL LEMOINE.
L'importante collection de Melobesiees recueillie par M. BOERGE-
SEN au cours de
ses voyages aux Antilles Danoises avait
ete con-
fiee
a
M.
FOSLIE,
de Trondhjem,
quo
la mort
a
surpris
(1909)
avant
qu'il
ait pu terminer son
travail.
II
restait
a determiner
un
certain nombre d'echantillons; M. BOERGESEN a eu
1'amabilite
de m'en proposer
1'etude.
Quelques-unes des
especes determinees
par
M. FOSLIE
etaient
nouvelles;
au
fur
et
a
mesure
de
ses
determinations
il
les avait
decrites dans
ses
Algologiske notiser,
mais
sans
les
figurer.
Aussi
ai-je
repris
1'etude
de
toutes
ces
especes
2
) de maniere a pouvoir donner
ici un memoire d'ensemble
') BORGESEN,
F., The algal vegetation of the lagoons in the Danish West
Indies.
Biologiske Arbejder tilegnede EUG. WARMING. K0benhavn 1911.
") Ce
travail a 6te fait au Laboratoire de Cryptogamie du Museum d'His-
toire
naturelle de
Paris (Professeur MANGIN, membre de
1'Institut).
10*
148
comprenant
la description
et
la
figuration de
toutes
les
especes
recueillies.
Les algues ont
ete recoltees par M. BOERGESEN a
S* Jan,
St.
Thomas
et Stc Croix
soit
par draguage
jusqu'a
des
profondeurs
de 30 a 40 metres,
soit a maree basse sur les cailloux, sur d'autres
algues,
et sur
les
recifs de polypiers
oil
les Melobesiees abondent
et
vivent
en
compagnie
des
Bryozoaires.
D'apres
la
quantite
considerable de materiaux
recueillis
il
est peu probable que Ton
trouve
a
1'avenir,
dans
ces
iles,
de
nouvelles
especes,
tout
au
moins d'especes jouant un
role important dans
la
flore.
La
flore des Melobesiees des Antilles Danoises
se compose de
20 especes
et represente une
grande
partie du nombre total
des
especes
recueillies
jusqu'ici
dans
1'ensemble des
iles des Antilles
(environ 32
especes).
Voici
la
liste des
especes
recueillies par M. BOERGESEN:
Lithothamnium mesomorphum
Fosl., var. ornatum
Fosl.
et Howe:
St. Jan.
sejunctum
Fosl.:
St.
Croix,
St. Thomas.
ruptile
Fosl.:
St.
Jan,
St.
Croix.
St. Thomas.
occidental
Fosl.:
St.
Jan,
St. Thomas,
St.
Croix.
Lithophyllum accretum
Fosl.
et Howe:
St.
Croix.
caribaeum Fosl.
:
St.
Jan,
St. Croix,
St. Thomas.
erosum Fosl.
:
St. Thomas.
intermedium
Fosl.
:
St.
Jan.
daedaleum
Fosl.
et Howe:
St.
Croix.
strictum
(Fosl.) Lemoine:
St.
Croix.
(?) absimile Fosl.
et Howe:
St.
Jan,
St.
Croix.
(?) propinquum (Fosl.) Lemoine
:
St. Jan, St. Croix, St. Thomas.
(Dermatolithon) prototypum Fosl.
:
St.
Jan,
St.
Croix.
Melobesia farinosa Lamx.
:
St. Jan,
St.
Croix,
St. Thomas
var. Solmsiana Falkb.
:
St. Jan,
St.
Croix,
St. Thomas.
(Lithoporella)
atlantica
(Fosl.) Lemoine:
St.
Jan.
(Litholepis)
affinis
(Fosl.) Lemoine:
St. Jan,
St.
Croix.
(Pliostroma) Chamaedoris
Fosl.
et Howe:
St. Jan,
St.
Croix.
Porolithon mamillare (Harv.
) Lemoine,
var.
occidentalis
Fosl.:
St.
Jan,
St.
Croix,
St. Thomas.
Boergesenii
(Fosl.) Lemoine
:
St.
Croix.
pachydermum
Fosl.:
St.
Jan.
On voit dans le tableau precedent que
le genre Lithothamnium
est represente par 4 especes,
le genre Lithophyllum par 9,
le genre
Melobesia
par
4
et
le
genre
Porolithon
par
3.
II y a
une
pre-
dominance
tres
nette
d'especes
en
croiites
car
deux
especes
seulement
sont des
especes
ramifiees,
et Tune
d'elles,
L.
striclum
est representee par une variete naine, non
ramifiee.
Au
point
de
vue
de
la
structure,
les
especes
crustacees
montrent
pour
la
plupart
un
caractere
interessant
:
c'est
la
149
reduction
de
1'hypothalle.
Je
rappellerai
que
ce
caractere
se
presente
indifferemment
chez
certaines
especes
de
chacun
des
genres Lithothamnium, Lithophyllum,
Porolithon.
Alors qu'il parait
rare
dans
les
especes
des
regions
europeennes,
ici
on
1'observe
dans
4 especes de Lithophyllum
et
2 especes de
Porolithon.
J'ai cherche
a tracer aussi exactement que possible
la reparti-
tion
et
les
affinites
des
especes
des Antilles
Danoises.
II n'y a
que
trois especes
qui
soient
connues
a
la
fois
dans
les
Antilles
Danoises
et dans
les mers europeennes
et
africaines.
Melobesia
farinosa
parait
etre
ubiquiste;
les
deux
autres
especes
vivraient
sur
la
cote
atlantique
africaine:
Porolithon
mamillare
au
Gap Vert,
a
St. Vincent
et
a
Algoa Bay
d'apres
HARVEY;
Porolithon
Boergesenii
a San Thome
dans
le
Golfe
de
Guinee,
oil
d'apres
FOSLIE,
il
serait
represente
par
sa
variete
africana.
Je
n'apporte,
pour ma
part,
aucune
contribution
a
ces
faits.
L'echantillon
de
la
collection
du Museum
d'Histoire
naturelle
de
Paris
qui
a
servi
a
creer
la
var.
africana
de
P.
Boergesenii
est de
si
petite
dimension
que
ce
serait
le
detruire
que de
1'etudier;
je
ne
sais
si FOSLIE a eu en
mains
un echan-
tillon plus important.
En admettant que 3 especes des Antilles ont une
repartition
assez
etendue,
il
reste
17
especes
qui
sont
limitees
a
la region
atlantique americaine:
12 especes vivent
soit en Floride,
soit aux
Bahamas
en meme
temps
qu'aux
Antilles
Danoises;
les
autres
especes,
au nombre
de
5,
n'ont
pas
jusqu'ici
ete
recueillies
en
dehors
des
Antilles
;
enfm
3
especes
de
petite
taille
ne
sont
connues qu'aux Antilles
Danoises.
Ainsi
il y a
peu
d'especes communes
aux Antilles
et
a
la
region africano-europeenne.
Mais,
d'autre
part
on
ne
peut pas
ne pas
etre frappe d'une ressemblance exterieure tres grande entre
certaines especes des
Antilles
et
d'autres
especes appartenant au
meme
genre
et
vivant
dans
la Mediterranee
:
ce
fait
est
si net
que,
pour
la
plupart
des
especes,
il
est
possible
de
mettre
en
regard de Tespece des Antilles une espece mediterraneenne d'aspect
quelquefois
si semblable qu'on pourrait les confondre
:
ce sont ces
ressemblances que
j'ai groupees dans
le tableau
suivant.
Antilles
:
Mediterranee
:
Lithothamnium rnesomorphum
var.
ornatum.
Lithothamnium lichenoides .
sejunctum.
Lenormandi.
ruptile.
crispalum.
occidental.
fruticulosum
var. cla-
rulata.
150
Lithophyllum intermedium.
daedaleum.
(?) propinquum.
(D.) prototypum.
Melobesia
(Litholepis)
affinis.
Lithophyllum
incrustans.
dentatum.
(?)
Notarisii.
(D.) papillosum.
Melobesia
(Litholepis)
Sauvageaui.
D'autres
especes montrent
d'autre part des
analogies remar-
quables avec
les especes de 1'Ocean
Indien
et du Pacifique
:
Antilles
:
Lithophyllum strictum.
Melobesia
(Lithoporella)
atlantica.
Porolithon pachydermum.
Antillarum.
')
Indo-Pacifique:
Lithophyllum frutescens.
Melobesia (Lithoporella) tnelobesioides.
Porolithon
encodes.
craspedium.
Pour
les especes L.
accretum,
L.
absimile,
L.
caribaeum,
L.
erosum, M.
Chamaedoris,
je ne connais pas d'especes
affines.
Gette
analogie
d'aspect,
souvent
tres
frappante,
entre
les
especes des Antilles Danoises
et
celles de
la
Mediterranee ou du
Pacifique
n'est qu'apparente
:
la structure offre souvent des carac-
teres
tres
differents.
Un
cas
typique
est
par exemple
celui du
Lithophyllum
intermedium;
par
son
aspect,
et
les
caracteres
de
ses conceptacles,
cette espece ressemble
a
s'y meprendre
a. Litho-
phyllum
incrustans de
la Mediterranee
et des cotes europeenne
et
africaine
de
1'Atlantique;
bien
plus,
les
deux
especes paraissent
vivre dans
les memes
conditions
et
forment
sur
les
rochers des
encroutements
qui
abritent
une
foule
d'animaux
;
or,
le
seul
examen de
la structure
eloigne
ces deux especes
1'une de 1'autre
;
L.
incrustans montre
un hypothalle
epais forme de rangees con-
centriques,
tandis
que
dans
L.
intermedium
1 'hypothalle
n'est
represente que par une unique rangee de
cellules.
Pour
d'autres
especes
les
differences
ne
seront
pas
aussi
profondes
; cependant
les dimensions des cellules,
1'aspect du tissu,
les dimensions des conceptacles sont autant de
caracteres
autori-
sant
1'individualite
des especes des
Antilles.
Si
j'ai
insiste
sur
ces
analogies,
ce
n'est done pas pour
dis-
cuter
la
valeur
des
especes
creees
jusqu'ici,
mais
c'est
plutot
pour
rechercher
les
relations
et
les
affinites
qui
existent
entre
les
especes.
Tableaux
de determination
des
especes des
Antilles Danoises.
Ainsi
qu'il a ete dit plus haut
les
especes des Antilles Danoi-
ses
representent
une
partie
importante
du
nombre
total
des
especes connues jusqu'ici dans 1'ensemble des
Antilles.
') Cette espece n'a pas
ete trouvee aux Antilles Danoises.
151
Les
especes
des Antilles inconnues aux Antilles Danoises
sont
les suivantes:
Lithophyllum acropetum Porto-Rico.
affine Porto-Rico.
congestum
St. Barthelemy.
platyphyllum
St.
Martin.
(Dermatolithon) polyclonum.
Lithothamnium aemulans Porto-Rico.
Archaeolithothamnium dimotum Porto-Rico.
Porolithon improcerum Jamaique.
Antillaruin Porto-Rico.
Mastophora Lamourouxi Guadeloupe.
Epilithon membranaceum Jamaique,
Porto-Rico, Guadeloupe.
D'autres
especes
ont
ete
signalees
aux
Antilles
par
suite
d'erreurs de determination
et
il ne doit pas en
etre tenu compte;
les
echantillons
appeles
Lithophyllum
incrustans
(COLLINS
1901)
doivent
sans
doute
etre rapportes
au Lithophyllum intermedium
;
Melobesia
confervicola de
la Guadeloupe
(MAZE
et SCHRAMM 1877)
est
le Melobesia
farinosa
d'apres FOSLIE
;
le Melobesia
callitham-
nioides de
la Guadeloupe egalement (Conquerant
in herb. BORNET)
est sans doute
le M. jarinosa var. Solmsiana
; d'autre part FOSLIE
a range dans
le Lithothamnium
occ.identale
var.
effusa des echan-
tillons appeles tout d'abord par
lui L. solutum var. effusa (FOSLIE
1906, c); de meme
les
echantillons nommes primitivement Poroli-
thon oncodes (WEBER
et FOSLIE
1904) ont
ete ensuite avec
raison
distingues,
sous
le nom de Porolithon pachydermum,
de
ceux de
1'Ocean Pacifique
;
de meme ceux nommes Lithothamnium Lenor-
mandi sont devenus Lithothamnium sejunctum;
enfin c'est certaine-
ment
par
erreur
qu'ont
ete
signales
aux
Antilles
les
especes:
Lithothamnium polymorphum
et L. amplexifrons (MAZE
et SCHRAMM
1877);
il
semble
egalement
que
le
Melobesia
Lejolisii
(COLLINS
1901) n'atteigne pas
la
latitude des Antilles;
certains echantillons
de M. farinosa depourvus d'heterocystes sont difficiles a distinguer
de
M.
Lejolisii.
Quant
au
Lithophyllum
(Derm.)
pustulatum
(COLLINS
1901)
il
serait possible que
les echantillons dussent
etre
ranges
plutot dans
la
var.
Udoteae du
Lith.
(D.) prototijpum;
les
deux
especes
sont
difficiles
a
separer
lorsqu'il
s'agit
de
petits
echantillons sur
algues.
I.
Conceptacles a sporanges ayant leur toit perc6 d'un certain nombre
de canaux.
f Tissu
differencie en hypothalle
et
perithalle;
hypothalle forme
de
files horizontales de
cellules
.
Lithothamnium.
152
II.
Conceptacles a sporanges ayant
leur
toit perce d'un seul pore.
t Tissu
differencie
en
hypothalle
(souvent
reduit
a
une
seule
range"e de
cellules)
et en
perithalle.
xx Tissu compose' entierement ou seulement en partie de rangees
de
cellules
separees
les
unes
des
autres
par
les
cloisons
tangentielles
e"paissies et plus ou moins soudees
les unes aux
au tres
Lithophyllum.
xx
Tissu
generalement
irrgulier
souvent
forme de
cellules de
formes et de dimensions varies
; presence de grosses
cellules
soit isolees soit en groupes de
5 a
8
Porolithon.
t Tissu non
differencie
en
hypothalle
et perithalle;
croutes
tres
minces formers d'une ou plusieurs rangees superposees
.
.
.
Melobesia,
Genre Lithothamnium.
I.
Especes en
croutes.
Croute
tres
adherente, lobee
et striee au
bord,
tres
mince,
sur
pierres.
Hypothalle:
cellules rectangulaires 10 a 15 //x 3 a 7//:
perithalle:
cellules ovoides 5a7/^x3a7 //.
Gonceptacles a sporanges 10
a 260
;j.\
40 canaux dans
le
toit;
conceptacles a cystocarpes 200
a 300 //
L. sejunctum Fosl.
Croute pen adherente formant souvent des lamelles libres orbicu-
laires, minces et fragiles, brillantes.
Tissu lache
; hypothalle: cellu-
les
rectangulaires:
10
a
14
jusqu'a
25/^x4
a
7 /a;
perithalle:
cellules arrondies de
10 a
12 /z x 7 a
10/jt a la base,
5 a 8//x5
a
7
11. au sommet.
-
-
Stdrile
L. mesomorphum
Fosl.
var. ornatum
Fosl.
et Howe.
Croutes peu
adherentes,
minces,
irre"gulieres,
d'aspect
variable.
Tissu
lache;
hypothalle:
files
entremelees,
cellules rect. -ovoides
20 a30,r/.x 7 a
10//.;
perithalle:
cellules ovoides de
10 a 15,a>c7
a
10 p..
Conceptacles a sporanges 500 a
700,y
L.
ruptile Fosl.
II.
Espece en branches.
Tissu forme de files laches distinctes
; cellules rectangulaires-ovoides
10 a 30 A X 6 a 10
IJL.
Souvent
sterile
L.
occidentals Fosl.
Genre Lithophyllum.
I.
Especes en croutes.
f Hypothalle forme d'une seule rangee de
cellules,
x Croutes
tres minces.
Surface rugueuse
; hypothalle
: cellules 5 a 7
;JL x 5 a 12 //
;
peri-
thalle
tissu compact,
cellules rectangulaires 3 a
6
IJL x 3 a 8 //.
Conceptacles
en
petits granules
convexes
de
80 a 120
//.
;
a
maturite
petites cavites
L. caribaeum
Fosl.
Cellules en
files
distinctes a la base,
plus serrees
a
la partie
suprieure, 5 a 7 p. x 7 //.
Conceptacles de forme ovale
; partie
centrale du
toit d^prime'e entoure par un rebord ovale
L. erosum
Fosl.
x Croutes
6paisses
mamelonnees
ou
pourvues
d'excroissances.
Perithalle
primaire
:
files
cellulaires
distinctes
;
cellules
rec-
tangulaires de
7 a
20/J-. x5 a
8//., disposees au meme niveau.
153
Perithalle secondaire:
files
serrees;
cellules de
10 a
22 p. X 5
a
12//., en rangees.
Ecorce
:
cellules bpxlOp.
Conceptacles
convexes
de
250 a 380 p.
;
sporanges 60 p. x 30 a
55 p..
Con-
ceptacles a cystocarpes convexes-coniques 200 a 350 p.
L.
dsedaleurn
Fosl. et Howe.
Hypothalle:
cellules
10 a 12,ax4//..
Perithalle:
cellules de
8 a
15 p. jusqu'a 20 p. x5 a 7 //, en rangees a
la base, en
files
distinctes
a
la
partie
superieure.
Conceptacles
150
a
300 p.
de diametre formant de
petites depressions a
la
surface du
thalle
L.
intermedium
Fosl.
t Hypothalle form6 de rangees concentriques.
Hypothalle:
cellules
7 a 12/^x5 a 10//.
Perithalle:
cellules
de 5 a 12p.x5 a
15/-/., au meme niveau souvent en rangees;
parois des cellules tres epaisses.
Conceptacles 300 a 400
//., de
forme
ovale, avec
la partie centrale du
toit deprimee ......
L. accretum
Fosl.
et Howe.
f Hypothalle forme
de
files
cellulaires non
disposees en
rangees
(structure aberrante dans
le genre Lithophyllum).
Croute adherente, lobee,
a surface
irreguliere.
Hypothalle epais;
cellules de 10 a 12/^x6 a
9/jt,
plus rare-
ment jusqu'a 18
et
22 p..
Perithalle
tres
epais,
cellules
de
3
a lp- x2 a3//. en
flies distinctes;
perithalle travers6 par des
lignes colorees.
Conceptacles
tres
serres,
convexes, de 100 a
160 p. de diametre
L.
absimile Fosl.
et Howe.
Croute peu adherente,
mince,
lobee,
quelquefois pourvue de
lamelles.
Hypothalle
files
serrees
rigides,
cellules
rectangulaires
15
a
35 p. x 7 a 12 p.
;
perithalle
:
cellules rectang. en rangees
:
7
a
lip x5 a 12 p..
Conceptacles
tres gros,
coniques,
de 300 a
1200 //, quelquefois prolonges par des
epines.
Sporanges 90 a
160 p. X 40 a 60 p.
L. propinquum
Fosl.
II.
Espece en branche.
Croute mince, lobee surmonte"e de nombreuses petites branches
cylindriques
non ramifiees
de 4 mm de hauteur
et
1 mm de
diametre.
Tissu forme de rangees
;
cellules rectangulaires 12
a
20/Jt x7 a lop
L. strictum
Fosl.
var. nana
Fosl.
et Howe.
Sous-Genre Dermatolithon.
Perithalle form6 entierement de hautes cellules rectangulaires pourvues
de
pores,
disposees
en
rangees.
Hypothalle
forme
de
cellules
obliques, contournees, de grande
taille.
Croutes
tres
adherentes
recouvertes
d'un
grand
nombre
de
tres
petites
lamelles.
Tissu
compose de
6 a
12 rangees qui
se separent
les unes
des autres;
cellules
de
7
a
35//. x 10 a
15//;
chaque
rangee
est
recouverte
d'une
rangee de
petites
cellules corticales de 3 a 5 p.
; hypothalle peu differencie
;
cellu-
les de 40 a 80 p.
Conceptacles a sporanges hemispheriques de
350 a 600 p;
sporanges:
60 a 80/^x35 a 50 p.
C.
a
cysto-
carpes coniques, 450 a 550 p.
L.
(D.) prototypum
Fosl.
154
Genre Melobcsia.
Croutes
sur algues,
d'abord
circulaires
formant
ensuite
des
croutes
plus etendues,
tres minces.
Thalle constitue en coupe par
3 ran-
gees
de
cellules. Vu de
dessus
tissu
caracterise
par
des hetero-
cystes.
Conceptacles de 60 a 250 p.
M. farinosa Lmx.
Sous-Genre Litholepis.
Croutes saxicoles,
tres fines, semblables a une poussiere puis formant
des thalles circulaires
;
thalle forme d'une seule range de
cellules.
Croutes
poussant
les
unes
au-dessus
des
autres.
Conceptacles
petits.
Cellules de 14 a 22 p. x 9 a 18 ,.
Conceptacles de 60 a 260 ,u.
M.
(L.)
affinis
(Fosl.) Lem.
Sous-Genre Lithoporella.
Croutes minces,
sur coraux,
poussant
les unes
au-dessus des
autres.
Thalle form6 d'une ou deux rangees de
cellules.
Conceptacles
tres
gros, coniques.
Cellules de 18 a 32
//. x 10 a 25 p. quelquefois atteignant
60 p.
< 40 p..
Conceptacles a sporanges de 500 a 800 p.
M.
(L.)
atlantica
(Fosl.) Lem.
Sous-Genre Pliostroma.
Croutes tres minces
sur
algues
et
pierres,
constitutes
par
plusieurs
rangees
de
cellules,
sauf
a
la marge
qui
n'est formee que d'une
seule rangee.
Conceptacles
petits, convexes.
Cellules de
7
a
13 x 8 a 10
/;..
Conceptacles
de
150 a 200 p..
M.
(P.) Chamsedoris
Fosl.
et Howe.
Genre Porolithon.
Hypothalle forme d'une rangee de
cellules.
Croute
epaisse.
Hypothalle:
cellules
20 a 25 /a x8//.
Peri-
thalle:
tissu
irregulier,
cellules de
7 a 18,u x 8 a 12//.
; grosses
cellules
isol^es
de
20
a
25 // x 18
a
20 p..
Conceptacles
a
sporanges
:
300 a 400 p.
P. Boergeseni
Fosl.
Croute mince,
lobee, peu adherente,
pourvue de nornbreuses
epines et de lamelles.
Cellules de 1'hypothalle peu differenciees
;
perithalle
cellules
10
a
20 p. x 7
a 15 p.
;
parois
des
cellules
minces.
Conceptacles
tres gros coniques de
1 mm, 4
P. mamillare Harv.
Hypothalle form6 de
files horizontales de
cellules.
Croute adherente sur coraux.
Hypothalle forme de quelques
files
;
cellules de 8 a 17 // x 4 a 10 p..
Perithalle tissu compact,
cellules 4 a
8 p. x 7 a 12 p..
Grosses
cellules en groupe de
8,
de 17 a 20
//. x 8 a 15 //.
Conceptacles a sporanges
convexes
150 a 250 p. de diametre
; sporanges de 60 a 70 p. x 30 a 40 p..
Cone, a cystocarpes convexes de 200 a 300^.
P. pachydermum
Fosl.
155
Lithothamnium
Phil.
1.
Lithothamnium mesomorphum
Foslie.
1901.
Lithothamnium mesomorphum
Foslie, New.
Melob.,
p.
5.
1906.
Lith. mesomorphum ornatum
Foslie
et Howe, New. Amer. Corall. alg.,
p.
129,
pi.
80,
fig.
2,
pi.
90,
fig.
2.
Lithothamnium mesomorphum
est represente dans
la collection
de
M. BOERGESEN
par
quelques
echantillons
appartenant
a
la
variete ornatum
;
ils forment de
petitcs lamelles
fragiles, de forme
d'abord
circulaire
puis
ensuite
orbiculaire,
fixees
seulement
par
un point de
la
face
inferieure ou par une extremite;
la marge est
blanche
et
legerement
epaissie.
Cette
espece
peut egalement
se
presenter
sous
1'aspect
de
croutes
qui montrent, comme
les
la-
melles, une surface
brillante;
ces
croutes
se detachent facilement
des coraux
sur
lesquels
elles sont
fixees
et elles ont une tendance
marquee
a
la formation ca
et
la de
petites
lamelles
orbiculaires
dressees.
Par son aspect
brillant,
sa surface
striee
et
ses gros concep-
tacles L. mesomorphum
rappelle
beaucoup
1'espece
atlantique
et
mediterraneenne L.
lichenoides
;
la
var. ornatum
a
aussi une
cer-
taine
ressemblance
avec
L.
expansum
de
la
Mediterranee,
en
particulier avec
sa
var.
tennis.
L. mesomorphum var. ornatum
est generalement
sterile
; dans
la forme type
les conceptacles
a sporanges ont de 350 a 600 /< de
diametre,
de forme peu
definie
;
leur
toit
est perce de nombreux
canaux;
les sporanges mesurent
100
a 140 ^ de
longueur
et 60 ^
de largeur.
En coupe L. mesomorphum montre
une
structure
tres lache
avec de larges
interstices entre
les
files
de
cellules;
rhypothalle
est forme de
cellules rectangulaires
; de
10 a 14
fj. de longueur
et
4 a
7// de
largeur,
et meme de
20
a 25 /^ x 4 a
7/^;
il
est
peu
developpe,
forme
seulement
de
quelques
files.
Les
cellules
du
perithalle qui
lui
font
suite sont
arrondies,
elles
mesurent
10 a
12 n x 7
a
10
fj.
pres
de
Thypothalle
et
vont
en
diminuant
de
taille
vers
la partie superieure de
la croute
oil
elles ne mesurent
que
5 a 8/^ x 5 a 7/7.
L'epaisseur des
croutes
est de 300 a 500^.
St. Jan:
Entre Cruz Bay
et Great
St. James, No.
2143,
profondeur
15 brasses; au large d'Annaberg, No. 1989,
prof.
15 brasses
Ma.
Repartition geographique:
L. mesomorphum
a
ete
signale
aux
lies Bermudes (Herbier BORNET, echantillons recoltes par
le General LEFROY
en 1873 et par M. FARLOW en
1881); Howe
1'a recueillie aux
lies Bahamas.
II n'avait pas encore
e"te
signale aux
Antilles
;
il
n'est
d'ailleurs
represente
que par quelques echantillons
recueillis a une certaine profondeur
;
il parait
156
done rare aux Antilles Danoises.
G'est une espece
a rechercher, a cause de
sa
fragilite,
dans
les
endroits
abrites
et
les
anfractuosites
des
rochers et
des
recifs.
2.
Lithothamnium sejmictum
Foslie.
1906.
Lithothamnium sejunctum
Foslie, Alg. Not.
II,
p.
13.
L. sejunctum forme,
sur
les
pierres,
de
petites croutes adhe-
rentes
tres
minces,
lobees
au
bord
et
liserees
de
blanc
sur
les
echantillons
sees;
Faspect
est
assez
voisin de
celui
de L. Lenor-
mandi commun
sur
les
cotes
europeennes
de
1'Atlantique,
en
particulier de
sa variete
sublsevis.
Les conceptacles
a sporanges
mesurent
160 a 260 //
de
dia-
metre;
leur
toit
est
perce
de
40
canaux.
Les
conceptacles
a
cystocarpes mesurent 200 a
SOO/^.
En coupe
verticale on observe
la presence de 1'hypothalle et
du
perithalle.
L'hypothalle est forme de quelques
files de cellules;
les
cellules
sont
rectangulaires,
legerement ovoides, de 10 a 15^
,
de longueur
et
3 a
1 p. de
lar-
geur.
Les
cellules du
perithalle
sont
ovoides,
de
5
a
7
//.
de
/l
longueur
et
3 a
1 p. de
largeur.
L'analogie d'aspect exterieur
Fig. 150.
Coupe verticale d une croute
.
de Lithothamnium sejunctum.
entre L. sejunctum
et L. Lenor-
mandi
n'est
pas
accompagnee
d'une analogic complete dans
la structure; en effet
les
cellules de
1'hypothalle
de
L.
Lenormandi
mesurent
15
a
22 // x 3
a
4/^;
elles sont rectangulaires
a
angles
vifs;
les
cellules
du
perithalle
sont
rectangulaires-ovoides
et
mesurent
6 a
9/^ x 4
a
5/^;
les
conceptacles a sporanges
et a cystocarpes sont un peu plus grands
et mesurent 200 a 400 //;
enfin
le
toit du
conceptacle
est dissous
dans
sa
partie centrale
et
il
reste
une
bordure
annulaire carac-
teristique.
St. Croix:
Christiansted.
St. Thomas cote Nord.
Repartition geographi que.
Cette
petite espece
n'a pas jusqu'ici
ete
recueillie en d'autres
localites.
3.
Lithothamnium
ruptile
Foslie.
1905.
Lithothamnium syntrophicumFosl.
f. ruptilis Fosl.
; Foslie, Botan. Saml.
(1904)
1905,
p.
18.
1907.
Lithothamnium ruptile Foslie, Alg.
Not.
Ill,
p.
5.
Lithothamnium
ruptile
se
presente
sous
Faspect
de
croutes
minces,
irregulieres,
souvent contournees,
poussant
les
unes
au-
157
dessus
des
autres
et
formant
ainsi
une
croute
complexe qui
se
libere de son substratum;
la croute peut s'enrouler sur elle-meme
en
certains
points
de
maniere
a
simuler
des
sortes
de
petites
coupes evasees ou
des
sortes de
branches
creuses.
L'aspect
est
en somme
assez
variable,
mais
les
croutes
se distinguent
de
la
plupart
des
autres
especes,
des
Antilles
parce
qu'elles
ne
sont
pas adherentes
au substratum.
Cette
espece
rappelle beaucoup,
Lithothamnium crispatiim de
la Mediterranee
et
L. syntrophicum.
Les conceptacles a sporanges sont de grande taille et mesurent
500
a 700 1
de diametre.
En coupe on observe que 1'hypothalle
est forme d'un
certain nombre de
files laches
et entremelees
;
les
cellules
sont
rectangulaires-ovoides
et
mesurent
20
a
30 //
de
longueur
et
7 a 10 /^
de
largeur.
Lorsqu'il y a formation d'une
excroissance
1'hypothalle
y
contribue en formant des
files
verticales dont les
cellules sont
rectangulaires
et mesurent
25
a, 30
IJL x 9 a 14//;
1'hypothalle
est continue
par
le
perithalle
dont
les
cellules
ovoides
et
gonflees
en
forme
de
ballon
mesurent 10 a 15// de longueur
et
7 a 10
tj. de largeur.
Fig
151
Croute
de
Lithothamnium
St. Thomas:
Thatch
Cay,
ruptile (grandeur
naturelle).
No. 1967
; S t. J an
: Au large de Cruz
Bay, No. 1826,
2142.
St. Croix:
White Bay, No. 1590.
Repartition geographique.
Cette espece a
et6 signalee a
St. Do-
mingue;
peut-etre
est-ce
la meme espece qui
aurait
ete
signalee aux Ber-
mudes sous
le nom de L. synlrophieum (FOSLIE
1901).
4.
Lithothamnium
occidentale
Foslie.
1906.
Lithothamnium fruticulosum
(Kiitz.) Fosl.,
var. occidentale Foslie,
Alg.
Not.,
II,
p. 12
1908.
Lithothamnium
occidentale
Foslie, Nye
Kalkalg.,
p.
3
(.
effusa
Fosl.).
Cette espece constitue
de
petits
massifs
formes de branches
ramifiees souvent coalescentes
;
1'aspect en
est souvent informe et
peu
elegant;
il
est probable que
cet aspect
resulte de conditions
de vie nuisibles a 1'espece,
car les branches sont quelquefois creuses
en leur partie
centrale
et
1'espece est souvent
sterile.
Des echan-
tillons mieux developpes, formes de branches
fines
et divergentes
ont
ete groupes par M.
FOSLIE dans
la variete
effusa.
158
En
coupe
le
tissu
est
compose
de
files
cellulaires
laches,
separees les unes des autres;
les cellules sont rectangulaires,
legere-
Fig.
152.
Thalles de Lithothamnium occidentals
(grandeur
naturelle).
ment
gonflees,
elles mesurent 10 a 20^, jusqu'a 32 p de longueur
et
6 a 10 // de largeur;
elles sont en somme de taille tres variable;
les
cloisons
ne
se
colorent
pas
fortement par
les
reactifs.
L'espece
a
montre
jusqu'ici
des
conceptacles
jeunes
ou
mal
developpes
;
cependant dans une
coupe
j'ai observe une tetraspore
qui
mesurait
180^
de
longueur
30 f*
et
75
fj. de
largeur.
St. Jan: Au large d'Annaberg No.
1989, profondeur
15 brasses
; au large
d'America
Hill,
No.
2072,
2003;
au
large de Cruz Bay No. 1826, 1917, 1727,
2221.
Entre St. Jan et St. Thomas,
(Dr. TH. MORTENSEN);
entro St. Jan
et Thatch
Island
No. 1995.
St. Tho-
mas:
Quest
de
Water
Island,
No.
1178, profondeur 20 brasses.
St. Croix: White Bay, No.
1590.
Repartition geographique.
Cette espece a
ete signalee
a
St. Do-
mingue. Aux Antilles Danoises
il faut noter son abondance
a
St. Jan
et sa
faible abondance
a
St.
Croix.
Fig.
153.
Files
cellulaires de Litho-
thamnium occidentale.
159
Lithophyllum
Phil.
1.
Lithopliylluui accretum
(Fosl.
et Howe) Lem.
1906.
Goniolithon accretum
Fosl.
et Howe, New Amer.
Corall.
Alg.,
p. 131,
pi.
85,
fig.
2,
pi.
91.
Cette espece
se presente
sous
Faspect
de
croutes
circulates
qui
se reunissent en formant des
croutes d'une
certaine etendue,
adherant
tres fermement au substratum
;
1'epaisseur est generale-
ment de 80 a 350 /*;
elle peut atteindre 1mm. 3;
elles sont lobees
au bord,
et
striees
;
la marge est un peu plus
epaisse;
a la limite
de
deux
thalles,
il
y
a
formation
d'un
rebord.
Cette
espece
recouvre L. caribaeum
et
est a son tour recouverte par L.
inter-
medium et L. propinquum.
La
surface
est
couverte
de
conceptacles
jusqu'a
la marge;
les conceptacles a sporanges sont convexes, peu saillants
;
la partie
centrale du
toit
s'affaisse legerement et
est entoure par un rebord
;
les
conceptacles
a
cystocarpes
sont
legerement
coniques
et
a
maturite laissent a leur place un trou
;
le diametre des conceptacles
est de 300 a 400 //.
En
coupe
L.
accretum
montre
un
hypothalle
compose
de
cellules
de
7 a 12 a x 5
a
10//,
disposees
a
peu
pres
reguliere-
ment en
rangees concentriques
;
les
cloisons separant
les rangees
sont
plus ou
moins
epaissies,
en
certains points
elles atteignent
5
fj..
Dans
les croutes minces,
1'hypothalle occupe
presque toute
1'epaisseur de
la croute
; dans des croutes plus epaisses, on observe
le
perithalle forme de
cellules
tres larges de 5 a 12// de longueur
et
5
a 15^
de
largeur,
les
membranes
des
cellules
sont
tres
epaisses
;
les
cellules
sont disposees au meme niveau
et en certains
points forment des
rangees.
En dehors
des
echantillons
de
BOERGESEN,
j'ai
etudie ceux
de HOWE
provenant des Bahamas;
on
remarquera que ma
des-
cription
basee
sur
1'etude
de
ces
echantillons
differe
de
celle
donnee
par FOSLIE
et HOWE;
ces
auteurs
ont
donne
pour
les
cellules
de
1'hypothalle
les
dimensions
14 a 27x8 a
14 /./,
et
pour
celles
du
perithalle
4 a
9/^.
D'ailleurs
la
figure
qu'ils ont
donnee
pi.
91
ne
ressemble
pas a
la coupe que
j'ai obtenue en
etudiant
1'echantillon
de Howe
des
Bahamas
;
cette
figure
rap-
pellerait plutot
la structure de Lithophyllum
absimile.
St. Croix: Sur caillou dans
1'eau peu profonde.
Repartition geographique.
L. accretum
a
6te signale en Floride:
Sands Key; aux Bahamas
; aux Antilles
il n'avait encore et6 signal^ qu'avec
doute a Porto-Rico.
160
2.
Lithophyllum
(?) caribaeum
Fosl.
1906.
Lithophyllum decipiens
Fosl.,
f.
caribaea
Fosl., Alg. Not.
II,
p. 18.
1907.
caribaeum
Fosl., Alg. Not.
Ill,
p.
22.
1909.
Fosl., Alg. Not.
VI,
p.
11.
Cette espece forme,
sur
les
pierres,
des
croutes
tres
minces
dont
la
surface,
sauf
sur
les
pierres
schisteuses,
est legerement
rugueuse
;
au debut
les croutes
se developpent en
grand nombre
et ne
recouvrent
pas completement
le
substratum;
puis
elles
se
reunissent
et forment
des
croutes etendues qui sont
tres souvent
cachees en partie par des especes dont
les
thalles sont plus
epais
comme L. propinquum
et L. intermedium
(fig. 159)
et L. accretum.
Les conceptacles forment de
petits granules souvent
si nombreux
qu'ils couvrent toute la surface
; leur diametre
est de 80 a 120^;
a maturite
ils laissent a leur place de
petites
cavites.
La
structure
de
cette
espece
a
pour
caractere
principal
la
reduction
de
1'hypothalle
forme
d'une
seule
rangee
de
cellules
rectangulaires
de
4
a
7
de
hauteur
et
5
a 12^
de
largeur.
|-
Le
perithalle
forme
un
"
2
<-f*
tissu
tres compact;
les
files
cellulaires sont
tres
serrees;
Fig.
154.
Coupe
verticals
du
thalle
de
jes
cenules sont
tres
petites
Lithophyllum caribaeum.
^
1
rectangulaires de
3 a 6^ de
longueur
et 3
a
8/^ de
largeur.
Dans
les echantillons
etudies
le
tissu ne montrait pas une disposition en rangees
tres nette
;
aussi
cette
espece
doit-elle
etre
placee
parmi
les
especes
aberrantes
du genre.
St. Croix:
Port
de
Christiansted,
dans
1'eau peu
profonde.
Estate
Northside,
sur
les
roches
exposees,
No.
1468.
St.
Jan:
Cruz
Bay,
No.
2196;
Great Cruz Bay. No. 1782, 1783.
St. Thomas: Pres de Water Island,
profondeur 15 brasses, No.
1161.
Repartition
geographique.
L.
caribaeum
parait
etre
une
des
especes
caracteristiques
des
Antilles
et
des Bahamas.
Aux
Antilles,
en
dehors des
localites indiquees,
elle
a
etc
recueillie a Porto-Rico
par Howe.
3.
Lithophyllum
erosuni
Fosl.
1906.
Lithophyllum erosum
Foslie,
Alg. Not.
II,
1906,
p.
20.
L. erosum forme
sur
les
cailloux des croutes
tres minces
(en
coupe
40^
environ)
qui
suivent
la
forme
et
les
asperites
du
substratum;
le contour
est
tres
decoupe.
Les
conceptacles
sont
petits,
peu
proeminents,
souvent
de
forme ovale
;
puis
le
toit
est deprime dans
la
partie
centrale
et
161
enfin
1'aspect
est
celui
d'une
petite
cavite
ovale
entouree
par
un
rebord
;
en
dernier
lieu
le
rebord
lui-meme
a
disparu.
En
coupe
1'un d'eux mesurait 80 // de
large
et 40 p de haul.
Le
tissu
est compose de
petites cellules
rectangulaires de 5 a
1
ft. et 10 ji de longueur et 7// de largeur, fortement
colorees par les
reactifs,
disposers en
files
distinctes a
la
base et plus serrees a la partie superieure.
L'hypothalle est represente par la rangee
basilaire de
cellules.
Je
n'ai pas observe
de rangees dans
le
tissu qui
par conse-
quent,
de meme que L.
caribaeum,
doit
etre place a part dans le genre Lithophyllum.
Fjg 165
Thalleg de LMo _
St. Thomas:
Pres dc
la
cote,
dans Ma-
pkyllum erosum.
gens Bay.
Repartition geographique.
L. erosum n'a pas encore
e"te signals
en d'autres
localites.
4.
Liihophylluin intermedium
Fosl.
1901.
Goniolithon? (Cladoliihon) intermedium
Foslie, New Melob.,
p.
15.
1906.
Lithophyllum intermedium
Foslie,
Alg. Not.
II,
p.
23.
L. intermedium forme a 1'etat jeune, de petits thalles de forme
circulaire,
lobes
ou
creneles
aux
bords,
qui
recouvrent d'autres
croiites plus minces comme L. caribaeum
et L. propinquum,
ainsi
qu'on
le
voit
fig.
161. A un
stade plus
developpe,
le
thalle
s'agrandit,
la
sur-
face
devient
mamelonnee
(Fig. 156)
et
lorsque plusieurs thalles,
cleveloppes sur
le meme substratum viennent a
se ren-
contrer,
leur bord se
releve en formant
une
crete
dressee, ondulee.
L'aspect de Palgue,
soit jeune,
soit
plus agee lorsque
sa surface
est mame-
lonnee,
rappelle
celui
de
Lithophyllum
incrustans
et de Pseudolithophyllum dis-
coideum;
ces
trois especes
si
differentes
de structure ont un aspect presque semblable
; toutes
trois vivent
dans
la zone
littorale,
sur
les
rochers
accessibles a maree
basse.
Les conceptacles tres nombreux forment une multitude de petits
points,
puis
de
petits
trous,
dont
la surface
du
thalle
est
veri-
tablement piquetee
;
leur diametre
est de 150
a 300 a.
En coupe on observe que
le
tissu est forme par
le perithalle
;
I'hypothalle
forme
seulement
la
rangee
basilaire de
cellules qui
11
Fig. 156.
Croute de Litho-
phyllum
intermedium (mar-
quee d'une
croix).
162
Fig. 157.
Coupe verticale de
la
croute
de
Lithophyllum
inter-
medium,
h, hypothalle.
mesurent
10 a 12^
de
hauteur
et
4/*
de
largeur.
Les
cellules
du perithalle mesurent
8
a 15 n
de longueur et peuvent
atteindre
20 n
;
leur largeur
est
5
a
7
//
;
les
cloisons
tangentielles
sont
epaissies
et
la
disposition
en
rangees
est
generalement
assez
nette,
surtout
a
la partie
inferieure du
thalle.
St. Jan: Cruz Bay, No. 2196; Great
Cruz Bay pres de
la cote No. 1783,
1782.
Repartition geographique.
L.
intermedium a ete signale aux Bermudes
(Wadsworth in herb. FARLOW)
; en Floride
(Waerdeman
herb.
FARLOW,
in
herb.
BORNET); aux Antilles
: Barbade (VICKERS
in herb. BORNET), Lassen (Herb. BORGE-
SEN), Jama'ique (COLLINS, HOWE) et avec plus de doute a Porto-Rico, (HOWE,
No. 2346, voir FOSLIE
1906,
p.
23).
5.
Lithophylluiu daedaleum
Fosl.
et Howe.
1906.
Lithophyllum daedaleum Fosl. et Howe. New amer. Corall. alg., p. 133,
pi. 83
et
84,
pi.
93 (microphotographie)
;
var. pseudodentala
Fosl.
et
Howe,
pi. 85,
fig.
1.
1909.
Lithophyllum daedaleum Fosl.
et Howe;
Foslie, Alg. Not. VI,
p. 37.
Lorsque
cette espece
atteint son complet developpement,
elle
forme,
sur les
cailloux,
des croutes de
mm
,5 a
2 mm
d'epaisseur,
qui donnent naissance a des mamelons
irreguliers ou a des sortes
de courtes branches,
plusieurs
fois ramifiees et souvent anastomo-
sees
;
ces branches ont environ
2 mm d'epaisseur
;
elles
sont
tres
epaissies
a
leur
sommet,
souvent tronquees ou meme deprimees
en
leur centre
; lorsque ces branches sont irregulierement dilatees,
elles apparaissent comme des
replis de 3
a 15 mm
d'epaisseur.
Dans
la var.
pseudodentata,
la plupart des branches sont tres
comprimees
et
sont
elargies
en
forme
d'eventail
a
leur
partie
superieure
;
elles peuvent
ainsi
atteindre une largeur de
2 cm.
Les
echantillons de M. BOERGESEN
se
presentent simplement
sous
1'aspect de mamelons irreguliers prolonged par de fines epines;
ils forment des thalles de
2 a
3 cm de hauteur.
La coupe
etudiee traversait une portion de la croute de 1 mm
600 ft
d'epaisseur. A
la partie
inferieure du
thalle on observe des
files
cellulaires
tres
distinctement
separees
les
unes
des
autres
;
les
cellules sont rectangulaires
et mesurent
7 a 20 p de longueur
et 5
a
8 n
de largeur;
les
dimensions moyennes
sont
12 a
17//
7 //
;
elles
sont
en
general
situees
au meme niveau
dans
les
163
\-fOf
differentes
files
;
les
cloisons
se colorent fortement par
les
reactifs
colorants.
Vers
la partie superieure de
la coupe,
le tissu prend un aspect
plus compact
:
les
files sont
plus
serrees
et
les
cellules
se dispo-
sent dans
leur ensemble en rangees horizontales
;
les cellules pour-
vues
chacune
d'un
pore,
mesurent
10 a 22^ x 5 a
12//.
Enfin
a ce second
tissu
ou perithalle
secondaire,
fait
suite une ecorce
formee
de
tres
petites
cellules
rectangulaires
tres
serrees,
plus
larges que hautes et disposees en rangees;
leur dimension moyenne
est 5^ x 10//.
Suivant
1'epaisseur
de
la
croute
etudiee,
elle
peut
etre
constitute
soit
seulement par le premier tissu (perithalle
primaire)
soit par
les deux tissus super-
poses (perithalles primaire et secondaire).
L'ecorce
peut
se
former a
la
suite du
perithalle
primaire
et
se
trouver
ainsi
intercalee
au
milieu
de
1'epaisseur du
tissu
;
les
cellules de 1'ecorce
se
recon-
naissent toujours a leur aspect et a leur
faible
coloration,
par
les
reactifs,
par
rapport aux autres
cellules.
L'hypothalle
parait
etre represente
par
une
unique
rangee
de
cellules
in-
colores a
la base du
thalle.
Les conceptacles
a
sporanges
sont
convexes,
peu
proeminents,
de
250
a
380 n
de diametre
d'apres
les auteurs;
les sporanges mesurent 60 // de longueur
on
>
or
j
i
rig. loo.
Coupe
verticale de
et 60 a 6b p de
largeur.
Lithophyllum daedaleum. mon-
Les conceptacles a cystocarpes sont
trant
la
superposition
des
->
,
^
.
differents
tissus.
convexes, Jegerement comques, et mesu-
rent 200 a 350^ de diametre.
Les conceptacles a antheridies sont
encore inconnus.
St. Croix:
Le port de Ghristiansted.
Repartition geographique.
Cette espece
a
ete
signalee aux An-
tilles:
Porto-Rico:
Salinas Bay pres Guanica
;
He Culebra; Santurce; San
Juan (FOSLIE
et HOWE 1906).
Elle vivrait probablement aussi au Venezuela:
Margaritaoen,
au
Bresil
(locality inconnue)
et a
Pile de
la
Trinidad
(herb,
du
British Museum,
echantillon nomme
precedemment
L. pallescens;
voir
FOSLIE,
1909,
p.
37).
11*
164
6.
Lithophyllum
strictum
(Fosl.) Lem.
var. nana
Fosl.
et Howe.
1901.
Goniolithon? (Cladolithon) strictum Foslie, New Melob.,
p.
14.
1906.
Goniolithon strictum Foslie; FOSLIE
et HOWE, New Amer. Corall. alg.,
p.
131,
pi.
82,
fig.
1.
1907.
Goniol. strictum
Foslie, Alg. Not.
Ill,
p. 16
(var.
fastigiata
Fosl.).
Lithophyllum
strictum
est
une
tres
jolie
espece
formant un
massif de branches tres ramifiees
;
1'aspect varie suivant le nombre
de ramifications
et
le
diametre
des
branches;
les
branches
sont
dressees ou un
peu
courbees
et s'amincissent
legerement vers
la
partie superieure
;
les
ramifications
sont
souvent
espacees
et
les
branches
prennent
naissance frequemment presque
a
angle
droit
sur
les branches principales
;
les
dernieres ramifications sont gene-
ralement bifurquees au sommet
et
Jes extremites sont arrondies.
L'espece
ne
parait
pas
etre
representee aux Antilles Danoi-
ses par des echantillons
types
;
M.
BOERGESEN
y
a
seulement
trouve
la
variete nana
qui en
differe
profondement
d'aspect.
Dans
cette variete 1'algue deve-
loppe sur des cailloux une croute
a
contours
largement
lobes;
d'autres lobes peuvent se former
ca
et
la
sur
la
surface
de
la
croute
;
cette croute ne s'epaissit
pas
et
clonne rapidement naissance a de
petites branches cylindri-
ques non
ramifiees, de
1 mm environ de diametre qui
se
dressent
verticalement
sur
toute
la
surface
de
la
croute,
sans
depasser
4 mm de hauteur.
En
coupe
les
echantillons
de
la
var.
nana
montrent
un
tissu
forme
de
rangees
de
cellules
rectangulaires
tres
larges,
mesurant 12
a 20 // de longueur
et
7 a 10
et meme 15
et
17
de
largeur.
Les
cellules
de
la
var.
nana
sont
plus
petites
que
celles
des
echantillons bien developpes de L. strictum type
;
ceux-ci,
sur
un echantillon de Floride m'ont montre des
cellules de
16 a 33 p
: 12
a 13/,
et FOSLIE
a meme
observe
en coupe
longitudinale
les dimensions suivantes 25 a 55 n x 15 a 25 p.
St. Croix: Longford; Long Reef, No. 1272, 1274;
Christiansted.
Fig.
159.
Aspect
extc-rieur de Litho-
phyllum strictum
var. nana.
165
Fig.
160.
Partie du
tissu
peri-
pherique (perithalle) des branches
de Lithophyllum strictum.
Repartition geographique.
L.
strictum
a
<He
signale
aux An-
tilles;
a
la Jamaique,
a Porto-Rico;
aux Bahamas
d'oii HOWE
en
a
rap-
porte
de
magnifiques
6chantillons
;
en
Floride
(AGASSIZ,
herb.
FARLOW),
Soldiers Key, Key West (HOWE, FARLOW
in herb. BORNET).
7.
Lithophyllum (?) absimile
Fosl.
et Howe.
1907.
Lithophyllum
absimile
Fosl.
et
Howe; FOSLIE, Alg. Not., IV, p. 27.
Je rapporte a cette espece des
croutes
de
St. Jan
dont
1'aspect
rappelle
a
premiere
vue
celui
de
Lithophyllum intermedium; la croute
est epaisse d'environ
1 mm, lobee
et
striee aux bords.
Les
conceptacles sont
tres
petits,
tres
serres
et convexes
;
ils
ne
paraissent
jamais
etre
enfonces
dans
le
thalle
ce
qui
les
differencie de ceux de Lit. intermedium
;
les conceptacles observes
en
grand
nombre
mesuraient
100
a
150
/j.
et meme
200^
de
diametre;
ces
dimensions
ne
sont
pas
eloignees
de
celles
indi-
quees par FOSLIE
et HOWE (120 a 160 u de
diametre).
Les spor-
anges n'ont pas encore
ete observes.
En
coupe
on
observe
un
hypothalle
bien
developpe;
les
cellules sont courtes,
elles mesurent
10 a 12^,
plus rarement
18
et
22
it.
de
longueur
et
6 a 9 a
de
largeur.
Le
perithalle,
tres
epais,
est forme de
tres petites
cellules de
3 a 7/* de longueur
et
2 a 4 n de
largeur, en
files separees
les unes des autres.
Le peri-
thalle
est traverse par des
lignes qui
se colorent par
les
reactifs
colorants,
et qui sont
distantes
les unes des autres de
10 a 20 ^
environ.
Les
cellules
perithalliennes rappellent
celles de L.
caribaeum;
cette
derniere
espece
forme
une
croute
beaucoup
plus mince
et
I'hypothalle
est
reduit.
Ces
deux
especes
ne
montrent
pas
la
disposition
en
rangees
caracteristique
du
genre Lithophyllum
et
doivent etre considerees comme des especes d'attribution incertaine.
Les
croutes
de
la
collection
de
M. BOERGESEN
out
ete
trouve"es
a
St. Jan: Cruz Bay, No. 2196, No. 1783, sur une
pierre en compagnie de L.
caribaeum, L. propinquum, L.
intermedium,
St. Croix:
Christiansted.
C'est
sans
doute
la meme
espece
qui
forme
une croute
tres
abimee
provenant de St. Croix;
la structure y
est
alteree.
Repartition
geographique.
L'espece
n'a
ete
jusqu'ici
signaled
qu'a
la Jamaique.
166
8.
Lithophyllum (?) propinquimi
(Fosl.).
1900.
Goniolithon
(Cladolithon)
Notarisii
Duf.,
f. propinqua
Fosl., New
or
crit.
calc.
alg.
(1899),
p.
21.
1906.
Gon.
Notarisii Duf.,
f. propinqua
Fosl.;
FOSLIE, Alg.
Not.,
II,
p. 15.
1907.
Gon.
solubile Fosl.
et Howe; FOSLIE,
Alg. Not., IV,
p. 21.
1908. Gon. propinquum Fosl.; FOSLIE, Nye Kalkalger,
p. 4
(f. imbicillaFosl.,
f.
solubilis
Fosl.
et Howe).
L. propinquum
forme
sur
les
pierres
des
croutes
a contour
lobe,
pourvues
de
gros
conceptacles
coniques;
ces
croutes
sont
bien
visibles
fig. 161,
oil
elles recouvrent L. caribaeum;
elles sont
elles-memes recouvertes a droite de
la
figure par L. intermedium.
Steriles,
les
croutes
ont souvent une sur-
face unie, sauf dans
la var.
imbicilla qui
montre
de
petites
lamelles,
et dans
la
var.
solubilis
qui
forme
sur
coraux
des
croutes
a
sur-
face
inegale.
Les
croiites se detachent
assez
facilement du
substratum
lors-
qu'elles
sont
agees.
Les conceptacles
souvent
developpes
en grand nombre
et
tres serres,
sont tres
larges a leur base et
Fig.
161.
Croutes
de
Lithophyllum
propinquum
pourvues de conceptacles a cystocarpes. Au centre
les croutes blanches marquees d'un v appartiennent
au
L. caribaeum
;
a droite un
thalle
de L.
inter-
medium marque" d'une double
croix.
de
forme
generale
conique
; le diametre
est de 300
(
a 1 mm. pour
les conceptacles
a sporanges,
de 500 a
1200
fj. pour
les
conceptacles
a cystocarpes
et
de 300 p
pour
les
conceptacles
a
antheridies.
Les
conceptacles sont
prolonges par
une epine caduque courte dans
les conceptacles a cystocarpes
et
plus
allongee
dans
ceux
a
sporanges.
Les
sporanges
mesurent
90 a 160 n de longueur
et
40 a 60 [i
de largeur;
les carpospores
observees dans une de mes coupes mesuraient 70 a 80 /* x 20 a 30//.
En coupe le tissu est forme d'un hypothalle et d'un perithalle.
L'hypothalle
est
forme
de
files
serrees,
rigides
;
les
cellules,
rectangulaires, mesurent dans
les
echantillons etudies
15 a 35^ de
167
11
tu
et
de
5
a
301*
Fig.
162.
Tissu perithallien de Litho-
phyllum propinquum.
longueur
et
7
a 12 //
de largeur;
cependant,
d'apres
Foslie,
elles
atteindraient 55 // de longueur.
Le
perithalle
est forme de
cellules
rectangulaires disposees a
la
fois en
files et en rangees
;
le
tissu presente un aspect compact,
les
cellules
sont
tres
serrees,
elles
mesurent
7
a
hauteur,
jusqu'a
25
12 p. de
largeur.
L.
propinquum
rappelle
1'espece
mediterraneenne
L.
Notarisii
et
aussi L. pacificum
du Japon.
St. Jan: Cruz Bay, No. 2196
;
Great Cruz Bay, No. 1782
; au large
de Cruz Bay No. 2086
(var.
imbi-
cilla); No. 2095, No. 1917.
St. Croix: Le port de Christiansted
;
St. Croix
1892.
St. Thomas.
Repartition geographique.
L. propinquum a ete recueillie a Porto-
Rico
:
Santurce, San Juan, He Culebra (HOWE);
a la Jamai'qne:
Montego
Bay (Hows);
elle
vit
egalement
a
la Barbade,
ainsi
qu'en
temoigne
un
echantillon de
la collection BOERGESEN
recueilli par Lassen;
enfm,
elle est
connue en Floride a Key West (Hooper)
et aux Bahamas (HOWE).
9.
Lithophyllum
(Dermatolithon) prototypum
Fosl.
1897.
L. prototypum
Foslie, On some
Lith.,
p.
18.
1901. Dermatolithon prototypus
Foslie, Rev.
syst.
surv.
Melob.,
(1900),
p. 22.
1901.
Goniolithon
Udoteae.
Foslie, New Melob.,
(1900),
p.
21.
1909. Lithophyllum (Derm.) prototypum Foslie, Alg. Not. VI, p. 49. Dermatoli-
thon prototypum
Foslie,
Alg. Not. VI,
p.
58.
Dans
la description de cette espece
je grouperai
les caracteres
de L. prototypum
et ceux de L. Udoteae
;
ces deux especes ne m'ont
pas
paru
presenter
de
caracteres
susceptibles
de
les
distinguer
1'une
de
1'autre
;
a mon
avis
L.
Udoteae
serait
une
variete
de
L. prototypum vivant
sur
algues.
L. prototypum
forme
sur
les coraux
et
les
coquilles,
et
sur
algues,
des
croutes
minces,
a contour
lobe,
montrant des
stries
concentriques
a
la marge
;
ccs croutes
sont
d'abord
orbiculaires
et
se soudent ensuite pour former des croutes de grande etendue;
elles sont d'abord
tres adherentes,
ensuite moins fermement
fixees
au substratum
; de nombreuses
petites croutes secondaires,
egale-
ment lobees au bord,
prennent naissance sur
la premiere
croute,
dont
toute
la
surface
est
ornee
de
petites
lamelles
orbiculaires
tres adherentes
; en regardant avec attention la
fig. 163 on verra
cette
disposition
tres
curieuse.
168
Les conceptacles a sporanges sont peu
eleves au dessus de la
surface du thalle, hemispheriques, legerement deprimes au sommet,
perces d'un pore
visible
a
la loupe
;
apres
la maturite des spores
il
reste
a
la
place du conceptacle une
cicatrice
circulaire.
Us mesurent 350 a 600 a de diametre,
principalement
400 a
500 n\
les sporanges mesurent 60 a 80
de longueur
et 35 a 50 //
de largeur.
Les
conceptacles a cystocarpes
ont
une
forme
plus
conique
et
mesurent
450
&
550^.
Des
conceptacles
de
120
a
220 n
de
diametre,
observes
par M.
Foslie
sont
sans
doute des
conceptacles
a antheridies.
La structure
est en rapport avec
la constitution de la croute
;
chacune
des
petites
croutes
secondaires
est
constitue
par
une
rangee de
cellules
;
en coupe on observe autant de rangees
qu'il
existait de croutes super-
posees
; on peut souvent
en observer
6,
quelque-
fois
12.
Chacune de ces
rangees
est
formee
de
hautes cellules rectangu-
laires pourvues chacune
d'un
on
deux
pores
;
elles
mesurent
le
plus
souvent 25 a So// de hau-
teur
et
10
a 15^
de
largeur
et
se
colorent
tres fortement parl'acide
iodhydrique
iode
;
les
cellules
des
rangees
in-
ferieures atteignent 40/*,
et plus rarement 65
et
85/,<, tandis que
celles des rangees superi-
eures n'ont que
7 a
20 ^.
Chaque rangee
de
cellules
est recouverte par
une rangee de
cellules
corticales de
3
a 5// de hauteur.
Comme dans toutes
les
especes du sous-genre Dermatolithon,
il y a une grande variation dans les dimensions des cellules suivant
les rangees
et meme dans une meme rangee.
Les rangees, compo-
sees des cellules perithalliennes surmontees de leurs petites cellules
corticales,
s'individualisent
souvent
les
unes
des
autres
apres
decalcification
et
dans
une
coupe
elles
sont
distant es
les
unes
des autres
(fig. 164).
Dans
les-echantillons etudies
la rangee de base ou hypothalle
etait
formee
de
cellules
assez
semblables
de
forme
a
celles
Fig.
163.
Lithophyllum
(Dermatolithon}
proto-
typutn sur coquille de Pinna.
169
des
autres rangees
;
au
contraire
les
autres especes de Dermatoli-
thon montrent generalement des
cellules
hypothalliennes obliques
et contournees,
tres
curieuses.
En resume cette
jolie
petite
espece a un
aspect
tres
carac-
teristique,
lorsqu'elle
est developpee
sur
des
pierres,
et ne peut
etre confondue
avec aucune autre
;
sur algues
(var.
Udoteae)
elle
a un espace plus restreint pour se developper;
elle forme de
petits
thalles
circulaires qui rappellent ceux de Lithophyllum pustulatum.
On
peut
cependant
noter
plusieurs
differences
essentielles
:
tout
d'abord
la
formation de
petites
lamelles
a
la surface du
thalle,
meme souvent sur des
thalles de
petite
taille;
puis, en coupe,
la
presence
des
cellules
corticales surmontant
les cellules de chacune
Fig.
164.
Coupe
a travers une croute complexe de Lithophyllum
(Dermatolithon) prototypum.
des
rangees,
tandis
que
dans
1'espece
L. pustulatum
il
n'existe
qu'une
seule
rangee de
cellules
corticales surmontant
la derniere
rangee
de
cellules
perithalliennes
;
enfin comme
il
a
ete
dit
les
rangees
de
cellules
sont
separees
les
unes
des
autres
dans
les
preparations;
les
dimensions
des
cellules
et
des
conceptacles ne
fournissent pas de caracteres
distinctifs de grande
valeur.
St. Jan: Cruz Bay; au large de Cruz Bay, No. 1826, 2086;
entre Cruz
Bay
et Great
St. James, No.
2143; Great Cruz Bay, No.
1782.
St. Croix:
Longreef 1274, sur
coquille.
var. Udoteae.
St. Jan: Great Cruz Bay, sur Galaxaura rugosa, No. 1832;
sur Udotea flabellum,
No.
1729.
St. Croix:
Lagune
de Christiansted,
sur
Udotea
flabellum,
No.
1305;
Port
de
Christiansted,
sur Galaxaura
rugosa,
No. 1232;
Little Princess sur Udotea flabellum,
1892;
Christiansted, No. 1272.
170
Repartition geographique.
Jusqu'ici L. prototypum
n'a
pas
te
signale en d'autres localites que
celles mentionnees
ici;
elle sera sans doute
decouverte dans
les regions avoisinantes
;
j'ai en effet rapporte a cette espece
un
echantillon
indetermine'
de 1'Herbier BORNET
recueilli
par HOOPER
en
Floride,
a Key West.
Melobesia Lmx.
1.
3Ielobesia farinosa Lmx.
1866.
Melobesia
farinosa Lmx.; ROSANOFF,
Melob.,
p.
69,
pi.
II,
fig
3 a
5,
10 a 12;
pi.
Ill,
fig. 2 a
13;
pi.
IV,
fig.
1,
10;
pi. VII,
fig. 12.
1905.
Melobesia farinosa Lmx.; FOSLIE, Rem.
north.
Lith.,
p.
96.
1908.
Melobesia farinosa Lmx.
; FOSLIE, Alg. Not. V, p. 16 (f. Solmsiana Falk.).
Melobesia farinosa
forme
sur un
grand nombre
d'algues
de
petites
croiites tres minces, generalement circulaires,
qui montrent
sur
les echantillons sees des strics radiales
et des stries
circulaires;
la surface en
est quelquefois poudreuse,
d'oii son nom.
Cette
espece
a
ete
remarquablement
bien
decrite
et
bien
etudiee par ROSANOFF.
Elle est, en principe, tres facile a determiner
au microscope,
par un simple examen
superficiel du
thalle,
sans
faire de coupes dans
le
tissu,
grace
a
la
presence
tres frequente
de
cellules
speciales
nominees
heterocystes.
On observe
en
effet
que parmi
toutes
les
files
de
cellules,
certaines
se
sont
arretees
dans leur croissance
et sont terminees par une
cellule plus grosse
que
les
autres
(fig. 1656, c);
cette
cellule
reste
souvent
incolore
lorsque
le
reste
du
tissu
est
colore
par
un
reactif colorant,
ou
sinon
se
colore moins fortement que
les autres
cellules.
Les
files
de
cellules
adjacentes
prennent
la
place de
la
file
arretee dans
son developpement, d'ou
il
resulte,
ainsi que
1'a signale le premier
ROSANOFF, un aspect sinueux des
files de
cellules.
L'abondance
des
heterocystes
est
tres
variable
suivant
les
echantillons etudies
(voir a
ce
sujet FOSLIE
1909),
sans
qu'il
ait
ete possible
jusqu'ici d'emettre une hypothese
sur
les causes qui
amenent
la formation des heterocystes.
Dans
les echantillons des
Antilles
Danoises
quelques
uns
meme
ne
m'ont
pas
montre
d'heterocystes
;
d'apres
les dimensions des
cellules
et
1'aspect du
tissu
j'ai
cru
cependant devoir
les ranger dans
la meme
espece,
mais
je
les
ai
inscrits
a part dans
la
liste
des
localites page 173.
Dans
cette espece
la
dimension
des
cellules
est
tres
variable
et
varie en particulier suivant
la nature du support
;
c'est
ainsi que
sur Zostere
elles sont de plus grande dimension que sur les autres
supports,
constatation
deja
faite
par
FOSLIE;
en
effet
dans
la
plupart des echantillons des Antilles Danoises,
les cellules mesurent
171
7
a 15
IJL
de
longueur
et
5
a 10 //
do
largeur;
sur
Zostere
elles
mesurent
15 a 22^ x 7 a 12^.
De meme dans des
echantillons
de
la Mediterranee
la dimension des
cellules
est de
12 a 20 /* x 7
a 10^,
sauf
sur
zostere
ou
elle
est
de
18
a
30 //
;
: 15
a
18
.
Tout en tenant compte de cette variabilite, on remarquera cepen-
dant que M. farinosa a des
cellules de plus
petite dimension aux
Antilles qu'en Mediterranee.
En resume
on peut
dire que dans
cette espece
la dimension des
cellules,
vues de
dessus,
sans
faire
de coupe,
varie
entre
7
et 30 ju
et
celle
des
heterocystes
entre
22
et
40//.
Les
cellules de M. farinosa sont de forme rectangulaire;
leurs
cloisons
se colorent
fortement
par
les
reactifs
en
particulier par
1'acide iodhydrique iode;
ces
cloisons
sont en general
situees au
meme
niveau
dans
les
differentes
files
et
s'alignent suivant des
lignes
concentriques
(fig.
165,
a,
b,
c;
voir
aussi
les
figures
de
ROSANOFF).
Dans
les echantillons que
je
range avec
les auteurs dans
la
type de
1'espece,
les
files
cellulaires
present ent une
assez grande
cohesion
:
le
tissu
a,
par
suite,
un
aspect
compact
et
regulier
(fig. 165 a, b)
; mais, dans
d'autres
echantillons
les
files cellulaires
sont plus
laches
(fig. 165
c,
d)
ou meme
paraissent couvrir
indi-
viduellement
sur
le substratum
(fig. 165 e), en affectant un aspect
irregulier
tres curieux.
J'ai pu
observer
toutes
les
transitions
entre
ces
types
de
structure
si
differents
au
premier
abord
et
j 'arrive,
pas
suite
a
la meme conclusion que FOSLIE qui
rangeait
les
thalles a
struc-
ture lache dans la variete Solmsiana Falk.
:
) du Melobesia farinosa.
Dans
la
variete
Solmsiana
les
heterocystes
sont
generalement
circulates,
tandis
que
dans
le
type de
1'espece
ils
sont
le plus
souvent
allonges.
Toutes
les
descriptions qui
precedent
s'appliquent a 1'etude
du
thalle vu
a
plat,
tel
qu'il
se presente
sur
les plantes qui
lui
servent
de
support.
En
coupe
verticale,
au
contraire,
le
tissu
est forme
de
trois
rangees
de
cellules,
la
rangee mediane etant
plus grande que
les deux
autres.
Les conceptacles
a sporanges
et a
cystocarpes mesurent 140
a 250^ de diametre
et
atteignent
300 // dans
la variete
borealis.
Cette
variete,
appelee Melobesia callithamnioides
par Falkenberg 1879
et SOLMS LAUBACH (Corallinaceae
d. Golf, von Neapel 1881)
fut
appele'e
Melobesia
Solmsiana
par FALKENBERG
(Rhodomelaceen
d.
Golf,
von
Neapel 1901.
Fauna und Flora des G.
v. Neapel,
p.
109)
pour
eviter
toute confusion avec
le M.
callithamnioides Crouan.
172
Les conceptacles a antheridies
mesurent 60 a 80^.
D'apres Ro-
sanoff,
les
cellules
qui entourent
1 'orifice des conceptacles a spo-
ranges sont un peu allongees et
relevees
;
ce caractere parait assez
difficile a observer sur des
echantillons
sees.
Les sporanges mesurent
d'apres FOSLIE 50 a 90/z x 30 a 50//;
j'ai observe dans un
thalle sur
zostere, de Ghristiansted,
des spo-
ranges de 40
a 50 // x 20 a
40//.
Comme
support M.
farinosa
type
a
ete
signale
sur Fucus,
Laminaria,
Cystosira, Padina, Sargassum, Chondrus, Rhodymenia,
a
Fig.
165.
Quelques exemples de variation de structure du
thalle de Melo-
besia farinosa vu de
dessus.
b varie"te type avec heterocyste
;
a, sans het6ro-
cyste;
d,
e var. Solmsiana;
c,
d, formes
de
transition.
Laurencia,
Ecklonia,
Bryothamniuui ,
Gigartina,
Caulerpa,
Carpa-
canthus, Chaetomorpha, Cymodocea, Posidonia, Potamogeton, Thalas-
sia, Enalis
et
Zostera.
La
variete Solmsiana a ete
signalee par FOSLIE
sur Peysson-
nelia.
sur
tubes
chitineux
d'hydroides,
sur
tubes
de
Serpules;
SAUVAGEAU
1'a
recueillie sur Valonia,
sur Cystosira,
sur Aglaozonia
aux Canaries.
FALKENBERG
1'a recolte
a Naples sur Aglaozonia.
Melobesia farinosa type (avec hdtdrocystes).
St. Croix:
Little Princess, sur Udotea
flabellum; Cassavagarden, No.
1389, sur Udotea flabellum; Christiansted zur Zostere;
Christiansteds' Lagoon,
173
sur Udotea flabellum; Port de Christiansted, No. 1228, sur Gelidium corneum;
Coakley Bay, No. 1358, sur Padina St. Crucis
; pres Christiansted sur coquille
; sur Padina
leg. Hansen; White Bay, No. 1555, sur Valonia macrophysa.
St. Thomas:
Quest
de Water
Island,
No.
1777,
sur
Valonia
ventricosa,
profondeur 30 metres;
pres
de Water
Island, No. 1101,
sur Udotea cyathi-
for?nis,
profondeur 30 metres.
St. Jan:
Cruz Bay,
No.
1822,
sur
Udotea
flabellutn; idem sur Halimeda discoidea, profondeur 30 metres; idem No. 1867,
sur Struvea elegans, profondeur 30 metres; au large d'America Hill, No. 2014,
sur Halimeda; au large d'Hermitage,
No.
2166,
sur
Zonaria
variegata pro-
fondeur 30 metres.
2) Sans heterocystes.
St. Croix: Christiansted surZostere; Long Reef sur Penicillus capita-
tus
;
cote sud
de
Pile,
sur Halimeda
incrassata,
leg. Hansen
;
Great Ponds
strand, No. 1369, sur Valonia aegagropila.
St. Thomas: Port de Charlotte
Amalia No.
120, sur Halophila; pres Water
Island, No.
1172,
sur Halimeda
incrassata var
simulans, profondeur 30 metres
; No. 119 sur Halophila.
St.
Jan:
Coral Bay, No. 140 B.
3) Melobesia farinosa
var. Solmsiana.
St. Jan:
Coral Bay No. 140 A; pres de Great St. James, No. 2087, sur
Zonaria variegata, profondeur 30 metres
; au large de Cruz Bay No. 1763 B,
sur
Udotea
flabellum, profondeur 30 metres.
St. Croix: Port de Christian-
sted No. 1311 sur Gelidium corneum
; Judith Fancy, sur Turbinaria
trialata ;
Cane Bay, sur
Udotea flabellum No. 1424.
St. Thomas:
Quest de Water
Island, No. 1173 C, sur Udotea
flabellum, profondeur 30 metres.
Repartition geographique.
Melobesia farinosa est une espece tres
commune,
connue
dans
toutes
les
mers du
globe;
aux Antilles
elle
a
e"te"
signalee a Cuba,
a
la Jamaique, a Porto-Rico,
a
la Guadeloupe,
a
la Desi-
rade,
a
la Barbade et a
la Martinique.
C'est cette espece qui a
e"te designee
par Maze
et Schramm
sous
le nom
de Melobesia
confervicola.
La
varie'te
Solmsiana parait vivre dans
les mers assez chaudes
; en Mediterranee
elle a
ete signalee
a Naples (FALKENBERG, SOLMS);
a Rhodes (NEMETZ
in REIN-
BOLD, Hedwigia, XXXVII, p. 87, 1898); dans PAdriatique (HAUCK, WILLE);
aux Canaries (SAUVAGEAU); Bahamas (HOWE).
Aux Antilles Danoises
elle
est aussi commune que
le M. farinosa type.
2.
Melobesia
(Pliostroma) Chamaedoris
Fosl.
et Howe.
1906.
Lithophyllum Chamaedoris Foslie et Howe, New Am. Corah
1
, alg., p. 134,
pi.
90,
fig.
1.
1908.
Lithophyllum Chamaedoris
Fosl.
et Howe; FOSLIE,
Alg. Not. V,
p. 17.
1908.
Melobesia (Pliostroma) Chamaedoris
Fosl.
et Howe;
FOSLIE,
Pliostr.
a new subg.,
p.
6.
Cette
petite
espece
forme
sur
les
Chamaedoris
des
croutes
d'une
epaisseur
de
60
a
150 //
qui
entourent
plus
on
moins
completement
les
tiges de
ces
algues;
leur surface
est
lisse,
et
la
couleur d'un rouge
assez
vif.
174
Les conceptacles a cystocarpes sont convexes ou subconiques
de 150 a 200^ de diametre
d'apres
les auteurs;
dans
les echan-
tillons de M. BOERGESEN
la dimension
la plus frequente est ISO//;
la
partie
centrale du
toit
s'affaisse
apres
maturite
et
disparait,
et
il
reste ensuite la partie peripherique formant rebord autour de
la petite
cavite
centrale.
Comme
dans
tous
les Pliostroma
le
thalle
est
compose
de
plusieurs rangees de
cellules
; on peut en observer jusqu'a 12
;
les
cellules
mesurent
7
a
13
/-/
de
longueur
et
8
a 10^ de
largeur
;
dans
la
partie
peripherique,
le
thalle
n'est
forme
que
d'une
seule rangee.
Vues de dessus,
sans
faire de coupe,
les
cellules mesurent
8
a
17 p. de longueur
et
7 a 13/z de largeur;
elles
sont
arrondies,
toutes
semblables
de
forme,
et
constituent
un
tissu
d'aspect
regulier.
Par
son
aspect
M.
Chamaedoris
rappellerait
d'apres
Foslie
Epilithon marginatum de
la
cote pacifique des Etats-Unis.
Le
thalle
est
d'autre
part
plus
epais
et
d'un
aspect
plus
unique
celui de M. farinosa] vues de dessus
les
cellules
se distinguent de
celles de M.
farinosa par leur forme
;
dans
cette
derniere
espece
elles sont rectangulaires
et sont
disposees en
rangees;
de
plus
il
n'y a pas de
cellules heterocystes dans M. Chamaedoris.
St. Jan: Rams Head, sur Chamaedoris annulata, profondeur 40 metres
No.
1940.
St. Croix:
cote sud
de
1'ile,
Mars
1892,
sur Cham, annulata;
White Bay, No. 1530 et 1575 sur Cham,
annulata.
Repartition geographique.
lies Bahamas.
Position systematique du sous-genre
Lithoporella.
Le
sous-genre Lithoporella,
auquel
appartient
1'espece L.
at-
lantica,
a
ete d'abord
place par M. FOSLIE
dans
le
genre Masto-
phora, puis a
ete considere par
lui comme un genre distinct.
J'en
fais ici un sous-genre de Melobesia.
Pour comprendre cette maniere
de
voir
il
n'est pas
inutile de rappeler
les conceptions successives
de M. FOSLIE au
sujet de
ces
especes, de classement difficile, pour
comprendre
la modification que
je propose
ici.
Le genre Mastophora a d'abord
ete
divise par M. FOSLIE
en
trois sous-genres:
1) Eumastophora
;
ce sous-genre reunissait
les especes a fronde
membraneuse,
divisee
ou
laciniee,
peu
calcifiee
et
par
suite
flexible;
il y
plac.ait
les especes:
M. Lamourouxi, M. macrocarpa,
M. plana
et
aussi M.
affinis bien que dans
cette
derniere espece
le thalle ne
soit pas
divise.
175
2)
Lithoporella
et Lithostrata
groupaient
les
especes
dont
le
thalle
est fortement incruste
et par
suite
cassant.
Lithoporella comprenait
les
especes dont
le
thalle
est forme
d'une
seule rangee de
cellules
1
),
sauf dans
la region des
concep-
tacles (M.
pacifica (Heyd.)
Fosl., M.
melobesioides
Fosl., M.
con-
juncta, M.
atlantica
Fosl.)
;
il s'opposait
a Lithostrata,
represente
par
la seule espece M.
lapidea dont
le
thalle
est forme de nom-
breuses rangees.
Les sous-genres Lithoporella
et Lithostrata
ont
ete
retires du
genre Mastophora
;
en
effet a moins de
modifier
la
definition de
ce genre
on
pouvait
difficilement y
laisser
des
especes formant
des croutes semblables
a
celles
des Lithothamniees
;
aussi Litho-
porella avait
ete considere par M. Foslie comme un genre distinct
de Mastophora
et ayant des affmites avec Melobesia;
a mon
avis
les
Lithoporella
ne
peuvent
pas
etre
separe
des Melobesia;
elles
representent une
simplification de structure
des Pliostroma,
sous-
genre de Melobesia, dont
le
thalle
est forme de plusieurs rangees
de
cellules
et
d'une
seule
rangee
au
bord.
II me
parait
done
logique de considerer Lithoporella comme un sous-genre de Melo-
besia
;
il
serait caracterise par la grandeur des
cellules
et des con-
ceptacles qui depassent de beaucoup
celles des
autres
especes de
Melobesia.
3.
Melobesia
(Lithoporella)
atlantica
(Fosl.) Lem.
1906.
Mastophora
(Lithoporella)
atlantica Foslie, Alg. Not.
II,
p.
27.
1909.
Lithoporella
atlantica Foslie,
Alg: Not.
VI.
p.
59.
Cette espece forme de petites croutes minces, de peu d'etendue,
qui poussent parmi
les
Bryozoaires,
sur
les polypiers morts
;
elle
ne pent
se reconnaitre a Paspect
que lorsqu'elle est fructifiee, grace
a
ses gros conceptacles coniques;
les conceptacles
mesurent
500 a
L_J
800 u de diametre;
les sporanges
'
Fig. 166.
Thalle de Melobesia (Litho-
Sont mconnus.
porella)
atlantica
forme d'une
seule
Le
thalle
est
generalement
rangee de
cellules.
forme par une rangee unique de
cellules,
plus rarement par deux;
les dimensions que
j'ai obser-
vees sont 18 a 32
[j. pour
la hauteur
et
10 a 25 // pour
la largeur;
') Dans les Lithoporella de nombreuses croutes peuvent se superposer les
unes aux autres
et en coupe on peut observer de nombreuses rangees
;
mais chaque croute
n'est constitute que par une seule rangee.
176
cependant des dimensions plus considerables ont
ete observees par
M. FOSLIE
:
32 a 60 // de hauteur
et 18 a 40 // de
largeur.
Cette
espece
rappelle
d'apres FOSLIE
le M.
melobesioides
de
FOcean
Indien
et
de
1'Archipel Malais
et
s'en
distingue
par ses
conceptacles plus
petits
et
ses
cellules plus
larges.
St. Jan: Au
large de Cruz Bay, No.
2095,
1727.
Repartition
geographique.
Cette
espece
n'a
pas
ete
signalee
en d'autres
localites.
4.
3Ielobesia
(Litholepis)
affinis
(Fosl.) Lem.
1906.
Litholepis
affinis
Foslie,
Alg. Not.
II,
p.
17.
Cette
tres
petite espece forme des croutes extremement minces
et peu
calcifiees
;
1'aspect
est
souvent
semblable
a
celui
d'une
poussiere
qui
serait
repandue
a
la
surface
des
coquilles
ou
des
cailloux
;
a
la
loupe on observe des
multitudes de
petits
thalles
qui
se reunissent en
s'accroissant
et forment
alors un petit thalle
de
forme
a
peu
pres
circulaire,
lobe aux
bords
;
on
remarque
quelquefois
la formation d'un nouveau
thalle dans
la partie cen-
trale d'un
thalle
ancien.
Les conceptacles
de
forme
hemispherique-conique,
mesurent
d'apres
FOSLIE,
les
uns
170
a 260 /*,
les
autres
60 a 120^;
les
sporanges sont encore
inconnus.
Je
n'ai
pas
observe de
coupe
verticale du thalle;
d'apres FOSLIE
les
cellules mesurent
14 a 22^
de longueur
et
9 a
IS fi
de
largeur.
M.
affinis montre
une
assez
grande
ressemblance
avec M.
(L.) bermudensis
Fosl.
et M.
(L.) Sauvageaui.
Position systematique du sous-genre
Litholepis.
M.
affinis,
placee
par
FOSLIE
dans
le
genre
Litholepis me
parait
devoir
etre
rattachee
aux
Melobesia,
en
ne
voyant
en
Litholepis
qu'un
sous-genre.
M. FOSLIE (New
Lith.
1905,
p.
5)
avait
d'ailleurs
insiste
sur
les
relations
de
ces deux
genres:
en
particulier
les conceptacles a sporanges sont semblables.
Au point
de
vue
de
la
structure,
les
especes
du
genre
Litholepis
ont
un
thalle forme d'une
seule rangee de
cellules
;
cette
structure peut
a mon avis resulter d'une simplication de celle de certaines especes
comme M. farinosa ou M . Lejolisii dans
lesquelles
le
tissu
sterile
est compose de
3 rangees
de
cellules
seulement,
dont
deux tres
petites
; autour d'un conceptacle
le nombre
des rangees augmente
dans
le genre Melobesia de meme que dans
le genre
Litholepis.
Litholepis pourrait done
etre considere comme
un sous-genre
de
Melobesia
caracterise:
1) par
sa
nature
saxicole
2)
par
son
177
thalle monostromatique
3) par
la superposition de croutes les unes
au
dessus
des
autres.
Les especes de Litholepis connues
jusqu'ici sont
: M. (L.) cos-
pica
Fosl., M.
(L.)
bermudensis
Fosl., M.
(L.) Sauvageaui
Fosl.,
M.
(L.)
indica Fosl.
Le sous-genre Litholepis a
certains
caracteres communs avec
Lithoporella
que
je
considere
egalement
comme
un
sous-genre
de
Melobesia]
la structure
est monostromatique,
et
il y a super-
position de
croutes dans
les deux
cas.
Mais
dans
le
sous-genre
Lithoporella
les
conceptacles
sont
beaucoup
plus
gros,
les
cellules
sont
plus
grandes
et
le
thalle
plus
epais.
St. Jan: Au
large
d'America
Hill, No. 2072;
No. 1967
(profondeur
16 brasses) No. 2104.
St. Croix: Northside, sur roches exposees, No. 1468;
Longford.
Repartition geographique.
M.
affinis
n'a
pas
ete
signale
en
d'autres
localites.
Porolithon.
1.
Porolithon
mainillarc
(Harv.) Lem.
var.
occidentals
Fosl.
1847.
Mclobesia mamillaris Harvey, Nereis
australis,
t. XLI,
p. 109.
1906.
Goniolithon
mamillare Harv.;
Foslie,
Alg. Not.
II,
p.
15
(f. occiden-
talis
Fosl.).
1909.
Gon.
mamillare Harv.;
Foslie, Alg. Not. VI,
p. 10.
Les
echantillons
de P. mamillare
des
Antilles Danoises
for-
ment des croutes lobees au bord surmontees de nombreuses petites
epines cylindriques de
3 /4 de mm.
a
1 mm.
x /2 de
hauteur environ.
Sur
la premiere croute
il y a
souvent formation de
petites
la-
melles
orbiculaires, formees ca et
la
au
milieu
des
epines,
et
qui
fig.
167.
Coupe
verticale du
thalle
n'adherent
pas
completement
a
de Porolithon mamillare.
la
croute.
Les conceptacles sont
tres
gros,
coniques,
renfles
clans
leur
partie mediane
;
leur diametre
atteint
1 mm
,4 environ.
En
coupe,
le
tissu
est
forme
de
grosses
cellules
a
parois
minces, peu
colorees par
1'acide iodhydrique,
elles sont disposees
irregulierement
et mesurent 10 a 20 // de longueur
et
7 a 15
/j. de
largeur;
1'hypothalle
est
represente
par
la
rangee
basilaire
de
cellules,
soit
peu
differentes comme
forme
et comme
dimension
des autres
cellules du
tissu,
soit plus allongees (20 a 22 a x 12
(
).
12
178
Dans
les prolongements en forme
d'epines qui surmontent
la
croute,
les
cellules
ont a peu pres
la meme dimension que dans
la croute:
5
a
15//, principalement 5 a
1 p. de longueur.
Por.
mamillare
var.
occidentalis
se
differencie
peu,
d'apres
FOSLIE, de P. mamillare type,
des
cotes
d'Afrique.
Cette espece
etait
placee
par
FOSLIE
dans
le
genre
Goniolithon,
genre
non
homogene dans lequel
les especes presentaient des types de struc-
tures
tres
varies.
Par
1'irregularite de son
tissu,
cette espece me
parait,
ainsi que P.
Boergesenii,
etre mieux placee dans
le genre
Porolithon,
a cote de P.
Reinboldi.
St. Jan:
Au large
de Cruz Bay, No.
2095, 1879
et No.
1826 (echan-
tillons abimes)
; au large de 1'Hermitage, No. 2181.
St. Croix:
Northside
sur roches exposees, No. 1468 -- idem
recolte en
1892.
St. Thomas:
No.
1030. Un echantillon de QUENSTEDT de 1848 appartient a cette meme espece.
Repartition geographique. Un e"chantillon indetermine de 1'herbier
BORNET, de Key West, Floride
(herb. FARLOW).
appartient a cette espece.
Cette espece vivrait egalement aux
lies du Cap Vert (Challenger Exp.,
DICKI 1875
et 1877); au Cap Vert a St. Jago (HARVEY 1847); a
St. Vincent;
a Algoa Bay (BOWERBANK in HARVEY 1847), sur la cote africaine; au Br6sil:
a Bahia (HARVEY
1847).
Peut-etre faudra-t-il revoir certaines des
localites
signalees par HARVEY, en
particulier
celles de Port Famine (Terre de Feu)
(DARWIN
in HARVEY
1847).
L'espece
signalee
a
Tongatabu
dans
1'Ocean
Pacifique (DICKIE)
est
le L.
erubescens
Fosl.
2.
Porolithon Boergcsenii
(Fosl.) Lem.
1901.
Goniolithon (Herpolithon) Boergesenii Foslie, New Melob.
p. 19.
1907.
Goniolithon (Hydrolithon)
Boergesenii
Foslie, Alg. Not. Ill,
p. 20 (var.
africana
Fosl.).
Les echantillons
recueillis par M. BOERGESEN montrent
cette
espece
a divers
etats
de
developpement
;
1'un
d'eux
forme
une
croute
d'environ
3 mm.
d'epaisseur developpee
sur
une
tige de
corail
;
la surface en
est
irreguliere
;
d'autres, plus
ages, forment,
sur des massifs de
polypiers,
des croutes mamelonnees ainsi qu'on
le voit sur
la
fig. 168.
L'algue
jeune
peut
former
une
croute
unie,
ainsi
qu'en
temoignent
les
echantillons
des
Bahamas
distribues
par Howe
(North American Marine Algae).
On a
signale
une
certaine
variation
dans
1'aspect
de
cette
espece,
suivant
la
nature
du
substratum
;
il
arrive
quelquefois
que des thalles de Bryozoaires
se developpent sur des croutes de
P.
Boergesenii
et que
celui-ci
recouvre
a son tour
les
thalles de
Bryozoaires
;
il
s'ensuit que Falgue presente des
aspects variables
et que
la structure peut
se trouver tout
a
fait
alteree.
179
Ainsi que
1'a remarque FOSLIE,
le
tissu hypothallien est repre-
sents par une seule rangee de cellules etroites,
placees cote a cote,
de 20
a 25 p. de longueur
et
8// de
largeur.
Le
tissu
perithallien
Fig.
168.
Croutes de Porolithon Boergesenii.
est forme de
cellules
tres variables
de forme,
ici
rectangulaires,
la
ovoides,
disposees
de
telle
sorte
qu'il
est
difficile
de
suivre
1'enchainement des
cellules constituant chaque
file
verticale.
Les
cellules mesurent
7
a 18 p de
longueur
et
8 a 12^ de largeur;
quel-
ques
cellules plus
grosses de 20 a 25^
x 18 a 20
[j.
sont
dispersees
ca
et
la
dans
le
tissu.
Les
cellules prennent,
suivant
les
regions du
thalle,
une
coloration plus
ou moins vive sans 1'influence du reactif
colorant,
de
sorte
que
dans
son
en-
semble
le
tissu
est
traverse
par
des
zones de
coloration
variable.
P. Boergesenii
rappelle
beaucoup
Por.
Reinboldi
de
1'Ocean
Pacifique,
par son tissu
irregulier, son hypothalle
forme d'ime seule rangee de cellules, et
par la presence au milieu du
perithalle
de grosses
cellules disseminees.
Les caracteres suivants permettent de
les
differencier
:
1) Les
cellules de
1'hypothalle sont plus petites dans P. Rein-
boldi (16 a 22^ x 10
a 20).
12*
Fig.
169.
Coupe
verticale
a
travers le thalle de Porolithon
Boergesenii;
b, hypothalle.
180
2) Les cellules du perithalle sont, dans 1'ensemble, plus grandes
dans P. Reinboldi (15
a 24
, x 6 a 15 /./).
3)
II n'existe pas de zones de
coloration visibles dans le tissu
de P. Reinboldi apres
action des
reactifs.
4) On
trouve
frequemment
la
presence
d'ecorces
anciennes
dans
le
tissu de P.
Reinboldi.
5) Les conceptacles a sporanges mesurent 300 a 400 p de dia-
metre dans P. Boergesenii et 350 a 700^ dans
P.
Reinboldi.
St. Croix:
Plusieurs echantillons,
en particulier
1'un
de Long Reef,
Bale de
Christiansted, No.
1272.
Repartition geographique.
En
dehors
des Antilles Danoises P.
Boergesenii a ete signale aux lies Bahamas (Howe), a la Barbade (echantillon
de Mile Vic KERS 1902 in herb. BORNET
et voir aussi FOSLIE
1901,
p.
21).
La presence de
cette espece a
e"te" signalee sur
la cote
africaine a San
Thome"
(Golfe de Guinee) par FOSLIE
(1907)
et HARIOT
(1908)
d'apres
les
echantillons
du
Museum
d'Historie
Naturelle
de
Paris
recolte's
par
M.
GRAVIER.
Ainsi que
je
1'ai
dit plus haut
(p. 149)
ce qui reste actuellement
de I'^chantillon ne permet plus de 1'etudier,
et
de
savoir
si
contrairement
aux donnees que Ton possede sur
les affmites des
etres du Golfe de Guinee,
P.
Boergesenii y
est reellement represente par une variete
africaine.
3.
Porolithon pachydermum
Fosl.
1904. Lithophyllum encodes
Fosl.,
f. pachydenna
Fosl., Alg. Not. V,
p.
5.
1909.
Lithophyllum (Porolithon) pachydermuni Fosl.,
Alg.
Not. VI,
p.
41
(f.
nexilis
Fosl.
et Howe).
Cette espece
se developpe
sur
les coraux
et
les
pierres
et y forme
des
croutes minces dont
1'aspect n'a
rien de caracteristique
et peut
etre
confondu facilement avec
d'autres
especes par
exemple L. propinquum,
Por.
encodes, L.
inter-
medium jeune
etc.
Les conceptacles a sporanges sont convexes,
peu saillants, de 150
a 250 // vue de la surface
;
les
sporanges
mesurent
60
a
70 // de
haut
et
30
a 40 n
de
large.
Les conceptacles
a cysto-
carpes sont convexes, de 200 a 300^ de diametre.
En
coupe on
observe
a
la
base un hypo-
thalle peu developpe forme de
cellules
courtes
qui mesurent
8
a 11
IJL de longueur
et
4
a 10 /^
de
largeur -
Le
perithalle a un aspect compact;
de Porolithon pachy-
les
cellules
sont
petites,
larges
par
rapport
a
un'groupe T^gros-
leur hauteur
et
generalement
tres
serrees
;
on
ses
cellules.
peut cependant observer dans
certaines parties
181
(fig. 170) des files separees les unes des autres;
les cellules mesurent
4 a S
tu
ou
8 a 11
,
de hauteur
et 5 a
12 [i de
largeur. Au milieu
du tissu existent
Qa et
la de
grosses cellules,
disposees par groupes
de
8;
elles
sont bien
visibles
et mesurent
17
a 20 // x 8
a
15/*.
La presence de
ces groupes de
cellules
differencie cette espece de
toutes
les autres especes des Antilles Danoises.
Par rapport aux
especes des regions plus eloignees, elle montre des affinites evidentes
avec
Por.
oncodes
de
1'Ocean
Indien
et
de
1'Ocean
Pacifique
(Funafuti,
Puamotou,
Sumatra, N elle Guinee).
Les deux
especes
se
differencient par un
certain nombre de caracteres
;
les
grosses
cellules
sont
dans L.
oncodes
par groupes de
3,
5 ou
plus
rare-
ment
8
;
les
cellules du
tissu sont dans 1'ensemble plus hautes
et
moms
larges.
St. Jan: Cruz Bay; Great Cruz Bay No. 1782.
Des echantillons de la
collection de M. BOERGESEN et provenant de QUENSTEDT,
1848, sans locality
doivent etre rapportes a cette
espece.
Repartition geographique.
P. pachydermum
a
e"te
signal^ aux
Bahamas (Howe)
(f.
nexilis)
et a
la Jamaique.
Un echantillon de L.
inter-
medium
de
la Barbade
recolte
par
LASSEN,
de
la
collection BOERGESEN
recouvre une croute de cette espece.
Bibliographic.
COLLINS.
The algae
of Jamaica.
Proceedings of the American Aca-
demy of Arts and Science,
t. XXXVII, No.
9.
Boston 1901.
FOSLIE.
1897. On some Lithothamnia. Det Kongelige norske Vidensk.
Selskabs Skrifter, 20 pages.
Trondhjem 1897, No.
1.
1900. New or critical calcareous algae. Det K.
n. V id. Selsk. Skrif-
ter.
Trondhjem
(1899)
1900, No. 5, 34 pages.
1901.
Revised systematical survey
of the Melobesiae.
D.
K.
n. Vid.
Selsk. Skrifter.
Trondhjem (1900) No. 5,
1901, 22 pages.
New Melobesise.
D.
K.
n. Vid. Selsk. Skrifter.
Trondhjem
(1900)
1901, No.
6, 24 pages.
1904.
Algologiske Notiser
I.
D. K. n. Vid. Selsk. Skrifter.
Trond-
hjem
1904, No.
2.
1905.
Den
botaniske
samling.
Kgl.
norske Vid.
Selsk. Aars-
beretning for
1904.
Trondhjem
1905.
1905.
Remarks on
northern Lithothamnia.
D. Kgl.
n. Vid. Selsk.
Skrifter.
Trondhjem
1905, 138 pages.
1906.
Algologiske Notiser
II.
D.
Kgl.
n.
Vid.
Selsk.
Skrifter.
Trondhjem 1906,
No.
2.
1907.
Algologiske
Notiser
III.
D.
K.
n.
Vid.
Selsk.
Skrifter.
Trondhjem
(1906), No.
8, paru
1907.
1907.
Algologiske
Notiser
IV.
D.
K.
n.
Vid,- Selsk.
Skrifter.
Trondhjem
1907, No.
6.
1908.
Algologiske Notiser V.
D. K.
n. Vid. Selsk. Skrifter.
Trond-
hjem 1908, No.
7, 20 pages.
182
FOSLIE.
1908.
Nye Kalkalger.
D. K.
n. Vid. Selsk. Skrif ter.
Trondhjem
1908, No.
12,
9 pages.
1908.
Pliostroma, a new subgenus of Melobesia.
D. K. n. Vid. Selsk.
Skrifter.
Trondhjem
1908, No.
11.
1909.
Algologiske Notiser VI. D. K.
n. Vid. Selsk. Skrifter. Trond-
hjem
1909, No.
2.
FOSLIE
et
HOWE.
New
American
Coralline
algae.
Bull,
of
the New
York Botan. Garden,
vol.
IV, No.
13,
8 pages, 14
pi. New York
1906.
HARVEY.
Nereis
australis
or
algae
of
the Southern
Ocean.
Londres
1847
-49.
LEMOINE (Mme Paul).
Structure anatomique des Melobesiees
(application a
la
classification). Annales Inst. O ceanographique de Monaco,
t.
II,
fasc.
1, 105
fig.,
5
pi.
Monaco 1911.
MAZE
et SCHRAMM.
Essai
de
classification
des
algues
de
la
Guadeloupe,
26me
edition.
Basse-Terre 18701877.
ROSANOFF.
Recherches anatomiques sur les Melobesiees. Mem. Soc. imp.
Sc.
nat.
et math, de Cherbourg,
[2],
II,
XII,
112 pages,
7
pi.,
1866.
WEBER et FOSLIE.
The Corallinaceae
of
the
Siboga Expedition.
Siboga
Expeditie LXI, 16
pi., 34
fig.
texte.
Leyden
1904.
Subfam.
2.
Corallineae.
Amphiroa Lamx.
1.
Amphiroa
rigida Lamx.
LAMOUROUX,
I. V. F., Histoire des Polyp,
corall.
flexibl.,
vulg. nommes
Zoophytes, Caen 1816,
p. 297,
tab. XI,
fig.
1.
ZANARDINI, G.,
Iconographia,
vol.
3,
p.
79,
tab.
99,
fig. B.
ARESCHOUG,
I.
E.,
Corallineae
in
J. AGARDH,
Spec. Alg.j
vol. II, pars
I,
p. 532.
SOLMS-LAUBACH, Die Corallinenalgen des
Golfes von Neapel,
p. 6,
tab. 1,
figs. 1, 11 (Fauna u. Flora d. Golf. v. Neapel,
4. Monogr.
1881). YENDO,
K., Corallinae verae Japonicae,
1902,
p.
6,
pi.
I,
figs. 56,
pi.
IV,
fig.
4;
Revised List
of
Coralline,
1905,
p.
3.
WEBER-
VAN BOSSE, A.,
Corallinae verae
of the Malay Archipelago
(in A. WEBER-
VAN BOSSE and M. FOSLIE, The Corallinaceae of the Siboga-Expedition, 1904).
var.
Antillana nov.
var.
A forma
typica
praecipue
differt,
planta
majore,
caespitibus
usque ad
6 cm.
altis,
ramificatione
magis
regulariter
dichotoma,
ganulis
ssepe
obtusis.
The
specimens
found
were
growing
in
large,
dense
tufts,
about
6 cm.
high. They are
fairly richly ramified, and the rami-
fication
is mostly a very regularly dichotomous one (Figs. 171 and
172). The filaments are thickest in the lower part, about 1
1,5 mm.,
183
and taper evenly to the sum-
mit where often the diameter
scarcely
reaches
half
the
length of the above mentioned
size.
In
the basal part
the
colour of the dried specimens
is a ligth red-violet, towards
the top almost white with a
blue-violet
tinge.
The branches are spread-
ing, the angle
of
the
dicho-
tomy
being
mostly
obtuse,
though
sometimes
acute.
The
joints
are
long,
often
Fig.
171.
Amphiroa
rigida Lamx.
var.
rparhino-
a
Ipno-th
of
more
Antillana nov.
var.
Part of a regularly
dichotomous
thallus.
(About
2
: 1).
than one cm., cylindrical, and
in their upper end, bifurcate, the nodes often (not always) occurring
at rather a long distance above the dichotomy, one
or sometimes
even
2 mm. above
it.
In the
upper
end
of
the
frond the
dichotomy
often
does
not
occur,
but the
filaments
are
divided by nodes
in a similar
way
as
that
found
in
the
ramified parts of the thallus.
Of the illustrations
I have
seen of
this species my plant
seems
to come nearest to the
above
mentioned
figure
of
ZANARDINI (Fig. B 1), but the
ends
of
the branches
of my
plant
are
less
tapering
and
not
so curved
as the ones in
ZANARDINI'S
figure.
From
SOLMS - LAUBACH'S
Fig.
172.
Amphiroa
rigida Lamx.
var.
description
(1.
C.
p.
7) my
Antillana
nov.
var
Part
of
a
more
plant
geems
to
fatter
some-
irregularlv ramified thallus.
About 2:1).
.
what.
He says:
Sie
zeich-
nen
sich durch unregelmassige Verzweigung und durch spitzwink-
lige, wenig divergente Richtung der Aeste
aus,
daher denn
stets
kompakte
dichte
Rasen
gebildet
werden".
As
described
above
184
my
plant
has
just
a
fairly
regularly
dichotomous
ramification,
and the angle between the branches
is
often
obtuse.
Judging from YENDO'S figure
(1.
c., pi. IV, fig. 4) the Japanese
plant
seems
also
to
be
more
irregularly
ramified
and
to
form
more compact
tufts than the West Indian one.
As to
the
anatomy
I
found
it
agreing very well with Mme
WEBER'S
excellent
description.
In
the
joints
the
central strand
consists
of two rows
of long
cells,
alternating regularly with one
row
of
short
cells.
The
long
cells
have a
length
of about 100 /j, the short ones
of about
20//
only.
The
cortical
tissue
consists of several
layers of
short
cells,
shortest at the periphery.
In the young
thallus the cortex
consists only
of
a few layers
of
cells,
in
the
older
one,
on
the
other
hand,
of
several, because the
cortical layer increases,
as the
plant
grows
older,
in
thickness
(comp.
SOLMS-
LAUBACH,
1.
c.).
As mentioned by this investigator and described
more
particularly
by Mme WEBER
the
nodes
of
Amphiroa rigida consist
of two rows
of
cells
(Fig.
173).
The
cells
in
these
rows
are
of
nearly
the
same
size and have thick walls, except in the upper
and
lower
ends where
they meet the
cells
of the
central
strand.
Here
the
transverse
walls
are
horizontally placed while the
cells
in the middle of
the node meet each other with oblique walls, being
in
this way more
firmly
connected.
As suggested
by Mme WEBER this might, perhaps, help to increase
the strength
of
the
node.
A good
illustration
of
the
node
is
given by YENDO
in
"Corallinac
verse
Japonic*",
pi.
1,
figs. 5
6.
To
judge
from
HARVEY'S
description
of Am-
phiroa
fragilissima
in
Nereis,
part
II,
p.
85
the
plant he has had before him seems to be the same as the present
one.
HARVEY'S
description seems
in
any
case
quite
to
agree
with my plant;
but,
in order to
settle exactly their
identity, an
examination
of HARVEY'S plant
is
of course necessary.
HARVEY'S
closing remark that
it
is "an exceedingly fragile species, of which
it
is almost impossible to preserve more than broken fragments"
is
also
quite
in accordance with my plant,
this being too
very
fragile.
Most probably
this quality has induced HARVEY to
refer
his
plant
to Amph.
fragilissima having
not
noticed
the
most
Fig. 173. Am-
phiroa
ngida
Lamx.
var.
Antillana nov.
var.
Part
of
the node show-
ing
the
acute
/iboSt
270:1).
185
characteristic
of
this
species:
the
swollen
padlike
ends
of
the
joints,
pointed out very
clearly
in Linne's
short diagnosis which
runs
1
):
"G.
dichotoma,
articulis
filiformibus
divaricatis,
apice
basique
latioribus"
and
described
later
on
by
LAMOUROUX
in
Hist.
d.
Polyp.
Corallig.
flexibl.,
p. 298
(first quoted by HARVEY)
in
this way:
"articulations
cylindriques
avec un
renflement
en
forme de
boulet
a
leurs extremites".
In ELLIS
and SOLANDER'S
description
of
their Corallina fragilissima (in Nat. Hist. Zoophytes
1786,
p. 123,
pi. 21,
fig. d)
this character
is not mentioned.
Their
diagnosis
of
the
species
runs
verbally:
"Corallina
dichotoma,
articulis
cylindricis,
eequalibus tevibus ramis
erectis".
This
dia-
gnosis agrees perhaps best with Amph.
rigida the padlike swollen
ends
of the
joints being not mentioned, but the upper bifurcate
ends
of
the
joints
characteristic
of
this
species
are
neither
mentioned, and
if we examine
their figure
the nodes except one
are drawn
at
the
dichotomy.
As an examination
of ELLIS and
SOLANDER'S
specimens
is not
possible,
their
collections,
as men-
tioned
earlier
(comp.
p.
89),
most
probably
not
existing
any
longer,
it seems to me the best course to regard Amph. fragilissima
and Amph.
rigida
in the
sense
of LAMOUROUX and
this the more
so, as LINNE'S short, but striking diagnosis of Corallina fragilissima
does not leave any doubt
as to the plant he had
before him.
This
species
has
been
found only once.
It was
growing
in
shallow
water
between
Cymodocea
manatorum
and
other
sea-
grasses
in a place somewhat
sheltered by coral
reefs.
St. Croix:
Rust up
Twist.
Geogr. Distrib.
:
Mediterranean Sea, West
Indies, Japan.
2.
Amphiroa
fragilissima
(L.) Lamx.
LAMOUROUX,
I. V.
F.,
Histoire
des
Polypiers
corallig.
flexibl.
vulg.
nomm. Zoophytes.
Caen
1816,
p.
298.
ARESCHOUG,
I.
E.,
in
J. AGARDH,
Spec. Alg., vol. 2, pars 1, 1851, p. 531. WEBER- VAN BOSSE, A. and M. FOSLIE,
The
Corallinaceaa
of
the
Siboga-Expedition,
Leiden
1904,
p.
89,
pi. XVI,
figs.
1,
2,
5
(ubi
synomyna
pluria).
KUTZING,
F.,
Tabulae
Phycologicse,
vol.
8,
pi. 39,
fig.
1.
Corallina fragilissima L., Systema
nat.,
ed.
12,
vol. 1,
p. 1305).
ELLIS,
J. and
D. SOLANDER, Zoophytes
1786,
p. 123,
pi. 21,
fig. d? (comp. remarks
above).
Amphiroa
debilis
Kiitz., Spec. Algarum,
1849,
p. 700.
HARVEY, W. H.,
Nereis Bor.-Am., Part
II,
1853,
p.
86.
LINNE, Systema Naturae.
Editio duodecima reformata.
Holmiae 1767.
Tom.
I, Pars
II,
p.
1305.
186
The specimens found seem
to
agree very well with
the
de-
scription
given by Mme WEBER
and
quoted
above.
The
most
characteristic
feature
of
this
species
is
that the long
cylindrical
joints
are swollen padlike
at both ends
in the older parts
of the
thallus (comp.
the
fig. b
of KUTZING,
1.
c.).
As pointed out by Mme WEBER the
central strand
consists of
a variable number
of
rows
of
long
cells,
interrupted
by
one
or
two rows
of
short
cells.
In
the
specimens
examined
by me
I
have found
4
6 rows
of
long
cells,
their
length
varying
from
about 55
90
(
, that
of the short ones from
15 to
30//.
The
nodes
have
nearly
the
same
anatomical
structure
as
that
found
in
the
joints,
only
that
the
walls
of
the
cells
are
somewhat
thicker and
not
calcified.
Mme WEBER
has
given
a
very fine
illustration
of the node
(1.
c.).
The conceptacles
form
small,
roundish,
prominent
cushions
along the sides of the
joints.
I have only found tetrasporic plants.
The tetrasporangia are about 50
(j. long and
25 // broad and often
taper upwards
in
such a way
that
the
uppermost
spore
has
a
conical shape.
Having examined the authentic specimens of Amphiroa cuspi-
data and A.
cyathifera
and
having
found
that
their anatomical
structure does not differ from that of Am. jragilissima Mme WEBER
comes to the conclusion that these two
species
are only forms of
the
present
plant.
When
stating
this Mme Weber
adds
:
"I do
not attach great importance to this
point, whether specimens are
more
or
less
slender,
if they agree on
all other points".
I
share
this view with Mme WEBER especially
as my plants differ much
in
this respect the varying strength of the plants seeming to originate
from the locality in
which
the plants
are
found.
This
is
easily
illustrated by an example.
Specimens found near Cruz Bay,
St.
Jan,
growing
in
an
exposed
place
where
the
waves constantly
dashed
the
plants,
form
very
compact,
dense
tufts
;
they have
comparatively
short and thick
joints,
the
diameter
of which
in
the middle
of
the thallus reaches a
length
of
about 460
/./.
On
the
other
hand
specimens
from
sheltered
localities
and
those
growing between and protected by
sea-grasses are more
slender,
forming loose and open tufts, with much longer and thinner joints,
their diameter reaching only a length
of about 190 //.
This
species
is very common along the shores
of the
islands
and
occurs
both
in
sheltered
and
exposed
localities,
in
shallow
water and
in
deep
sea down to a depth
of
10 fathoms
or
even
more.
It
often
grows
abundantly upon
coral
reefs
and
here,
187
together
with
Jania
adh&rens
and
Corallina
cubensis,
covers
large extensions.
It
is
a
favoured
refuge
of many
small
algse which
find
a
comparatively
quiet
growing
place
among
its
rigid
filaments.
Besides many red algse,
e.
g. Hypnea, Spyridia etc., Cladophoropsis
membranacea
especially
settles
itself
here
and
often
grows
so
vigorously
here
that
it
quite
covers
the
host
plant
and
together
with
it
forms
quite
thick
carpets
on
the
rocks
over
which
the
surf
constantly
breaks.
The
small
forma reducta
of
Caulerpa
racemosa,
mentioned
in
Vol.
I,
p.
151
was
found
in
such
a
locality
growing
between Amphiroa
fragilissima and
in
Fig.
123
in
the same
volume
the
var.
occidentalis
of
Caulerpa
racemosa
is shown creeping between
the densely
felted filaments
of this
alga.
It has been
collected with tetraspores
in January
March.
Geogr. Distrib.
:
West
Indies, Indian Sea.
Corallina
(L.) Lamx.
1.
Corallina
cubeiisis (Mont.)
Kiitz. emend.
KUTZING, Tabulae phycologicse, vol. 8, p. 37, pi. 77,
figs,
e, f (non
fig. d).
Jania
cubensis
Mont,
in
KUTZING,
Species
Algarum,
1849,
p.
709;
MONTAGNE,
Sylloge gen. specierumque Cryptogamarum, 1856,
p.
429.
Up
to
the
present
day
this
species
has
been
considered a
doubtful
one and
it
cannot
be
denied
that
the
description
of
MONTAGNE
is, indeed, very poor and even
misleading.
It is described previously in KUTZING'S
"Species
Algarum";
the
diagnosis,
the
same, that
is found in MONTAGNE 's "Syl-
loge",
1849,
p. 429, reads verbatim:
"J.
intricata, subsetacea,
filiformis,
teres,
al-
terne
ramosa
vel
subdichotoma,
ramis
subpinnatis,
pinnis
ciliiformibus
paucis
patentibus subulatis
;
articulis
elongatis,
diametro
4
6 plo
longioribus,
primariis
clavatis, pinnarum
cylindricis.
Alt.
1 /-1"".
- Cuba (v.
s.).
"Spec,
dedit
cl. MON-
TAGNE",
is added by KUTZING.
This description might agree in some
points with my specimens, but it disagrees
plant.
(About 6:1).
188
absolutely with my plant, with its mostly opposite branches, when
it
is
said
in
the
diagnosis
:
"alterne ramosa
vel
subdichotoma".
Thus
an
examination
of
the
original
material
was
highly
desirable, and
I am greatly indebted to Mme WEBER
for the per-
mission
to
examine
the
original material
sent by MOMTAGNE to
KUTZING and preserved
in
his herbarium, now
in the possession
of Mme WEBER.
This
specimen
has
also
a
special
interest
on
account
of
the
fact
that
the
only
existing
illustration
of
this
species, namely that in KUTZING'S "Tabulae"
(1. c.), is based upon it.
After the examina-
tion
of
the
material
it at once became evi-
dent
that
it was
a
mixture
of two
spe-
cies present
in nearly
the
same
quantity,
namely a form of the
plant which
I in a fol-
lowing page call Jania
adhaerens and another
plant, the present one,
for which
I keep the
name
cubensis.
It
is
interesting to see that
KUTZING very correct-
ly has illustrated both
species,
his
fig. d
re-
presenting Jania ad-
haerens
while
figs,
e
and
/
are
Corallina
cubensis.
Before entering upon a description of this plant
I further want
to point out that in my specimens,
too, Jania adhaerens
is often
abundantly present.
Besides,
Corallina cubensis
also,
often grows
intertwisted among Amphiroa fragilissima.
After
these
introductory
remarks
I
shall proceed
to
give a
description
of the plant based upon my own
material.
Corallina cubensis
grows
upon
rocks
and
corals
and
forms
low dense
tufts about
1
2 cm. high,
often spreading widely.
The
slender
filaments
are
densely
crowded,
fastigiate
and
mixed
up
together.
The
branches
issue
as
a
rule
immediately
below the nodes (Fig. 174), but the ramification
is very
irregular.
Fig.
175.
Corallina cubensis (Mont.)
Kiitz.
Upper
part
of
a
plant with more
or
less
verticillated
branches and a tetrasporic conceptacle. (About 16 :1).
189
As a
rule
it
is
opposite,
but some-
times 3
5 or more verticillated bran-
ches are found (Fig. 175, 176).
These
branches
are
generally
of
a
very
different
strength,
some
being vigo-
rous,
others
delicate. Now and then
too, a single branchlet
is issued from
each
joint or they are quite destitute
of
branches.
And
what
especially
contributes to make the
ramification
irregular are
the many adventitious
branches (Fig. 177). These often grow
out below the ordinary branches, but
they may
also
issue
almost
every-
where from the
joint
e. g.,
as shown
'in
Fig. 177,
from the middle
of
the
joint.
Some
of
the
branches,
the
most
vigorous,
grow
out
to
main
filaments like the mother-branch, but
most
of them become
short branch-
lets
only.
These
branchlets
are un-
divided,
or they may
bear
a
single
or a few opposite branches.
The branchlets taper evenly upwards
to
their apex.
At their base the branchlets are about 100 a thick,
at
their
upper
end
they
often
scarcely
reach 35^ in diameter.
In the main filaments
the
joints
are
about
180
thick, somewhat
thicker in their upper
end,
thinner
in
the
lower one
; their length
reaching 600// or more.
Once in a specimen
I
found
a
few
of
the branchlets ending
in
small
attachment
discs
(Fig. 178).
Fig.
177.
Corallina cubensis (Mont.)
Kiitz.
Joints
yjie
}} ase
O f ^e
with adventitious branches.
Drawn from a decal-
cified specimen.
(About
18:1).
plant consists
ol pro-
Fig.
176.
Corallina
cubensis
(Mont.)
Kiitz.
Summit
of
a
slender
plant.
(About
18: 1).
190
strate decumbent branches,
fastened to the substratum by means
of haptera.
As to the anatomy the central strand
in the
joint commonly
consists
of 4 rows of
cells; these are about
100
/j. long and about
12 n broad;
the
cells
in
the
nodes
are almost
of the same
size,
longest
in
the middle,
and
growing
shorter
near
the
periphery
(Fig.
179).
Tetrasporic conceptacles
(Fig. 175, 180) have been found now
and then.
These
are urn-shaped and
are produced
in the upper
Fig.
178.
Corallina
cu-
bensis
(Mont.)
Kiitz.
Branchlets
ended
with
small discs. (About 20
: 1).
Fig. 179.
Corallina cuben-
sis (Mont.)
Kiitz.
Longi-
tudinal section of the node.
(About 200 :1).
joint
of
the
branchlet.
They
are
rarely
destitute
of
ramuli
(horns),
mostly
bearing
2
5
ramuli
verticil! ately
placed round
the middle
of the
conceptacle.
The conceptacles
are about 450
tj.
long
and
270 //
broad.
The
tetrasporangia
are
transversely
divided, nearly cylindrical or somewhat curved with rounded ends,
about
ISO// long and
70 // broad.
Corallina
cubensis
seems
to
be
rather
common
along
the
shores
of the
islands;
it
is found
in depths from
5
10 fathoms
of water and occurs often
in the open sea
in places where strong
currents
prevail.
It
is generally associated with other corallineous
algae,
e.
g. Amphiroa fragilissima and Jania adhaerens.
191
St. Croix:
off Frederiksted,
in White Bay.
St. Jan:
off America Hill
and
in several places
in the sound
between
this
island and St. Thomas.
Geogr. Distrib.
:
West
Indies.
Fig.
180.
Corallina cubensis (Mont.)
Kiitz.
Transverse section
of a
tetrasporic conceptacle.
(About 80
: 1).
Jania Lamx.
In various papers YENDO *) points out that the most charac-
teristic feature by which Jania
is distinguished from Corallina
is
the dichotomous ramification of the
filaments
as
against the pin-
nated branches
in
Corallina.
I
agree with YENDO
in
this point
of view.
1.
Jania pumila Lamx.
LAMOUROUX,
I. V. F.,
Hist. Polyp,
corallig.
flexib.,
1816,
p.
269,
pi.
9,
fig.
2.
ARESCHOUG,
I. E.
in
J. AGARDH, Spec.
Alg.
vol.
II,
p. 559.
YENDO,
K., Principle of systematizing Coralline (The Botanical Maga-
zine, Tokyo,
1905,
vol. XIX,
p.
123) and A revised
list
of Coralline
(Journal
of the College
of Science, Tokyo
1905,
vol. XX,
p.
2).
192'
Corallina pumila (Lamx.)
Kiitz.,
Tab. Phycol.,
p.
39,
tab.
83,
fig.
1.
HAUCK,
F.,
Meeresalgen von Puerto-Rico
in ENGLER,
Bot.
Jahrb.,
9.
Bd.,
1888,
p.
465.
HEYDRICH,
F.,
Beitrage
zur
Kenntnis
der Algenflora von
Ost-Asien (Hedwigia
1894,
p. 301).
This
little
plant grows
epiphytically upon
larger
algae,
e.
g.
Turbinaria and Zonaria.
It
is fastened to the host-plant by means
of a small roundish disc.
In the specimens examined by me the disc
was about 400 //
in diameter.
From the
surface
of
this
disc the
erect filaments
arise;
at
their base,
where
they
are attached to
/
the
disc,
a
node
is
always
present.
As
the
specimens
showed
some
differ-
ences
according
to
their
growing
upon
Turbinaria or Zonaria
I
wish
to
describe
them
separately and
begin with those upon
Turbinaria (Fig. 181).
This was growing
in
a very exposed
place
at
Judith Fancy
on
the north
side
of St.
Groix and on account
of
this the specimens
of Jania
had
also
a
Fig. 181.
Jania pumila Lamx.
Habit of a plant
rather robust
appea-
with
cystocarpial
and
antheridial
conceptacles
growing upon Turbinaria.
(About 25:1).
ranee.
The erect filaments
are
of very variable
size and development. Some of them consist
of a single joint which on
its top bears a conceptacle,
others are
longer, a few times dichotomously divided, ending in conceptacles,
if they are not throughout vegetative.
In the basal part
of
the
filaments
the vegetative
joints
are
mostly oblong-cuneate with broadly rounded top and very
atten-
uated
base,
in the upper part nearly
cylindrical,
tapering some-
what to
both ends.
The
first mentioned
joints
are about 200
;j.
long,
about
150 //
broad
at
their
upper
end
and
70 p
at
their
base, but much larger ones occur;
the more
cylindrical joints
in
193
the upper ends
of
the
filaments
are about
250
[j. long and about
80
[j. broad
in the
middle.
The antheridial
and
cystocarpic
conceptacles occur together
in the same plant
(Fig.
181),
while
the
tetrasporic
conceptacles
occur
in separate
plants.
As pointed out by HAUCK
(1.
c.)
the
tetrasporic and female
conceptacles
are developed
in
the
basal
joint
in the uppermost
dichotomy.
This
joint
is
cuneate
of shape
;
it
is
large,
of very
variable length, often more than 800^
long; the breadth,
at the upper end,
where
the
conceptacles
are
found,
seems on the other hand less variable,
about 250^.
In
the
tetrasporic
conceptacles
(Fig. 182) the hornlike prolongations
at
both
sides
of
the
conceptacles
mostly consist of two nearly cylindri-
cal joints, while in the female concep-
tacles these
horns
consist
only
of a
single joint.
But having seen
so very
few plants
I
dare
not say
that
this
is
always
the
rule
;
in
the
female
conceptacle the joints in the horn are
about 60
70 // broad and about 300
[j.
long,
while
in
the
tetrasporic
the
lowest joint in the horns is about 70^
broad and 400^ long, the upper joint
a
little
thinner
and
shorter,
about
230 ^ long.
The
joint
with
the
antheridial
conceptacles are ovate
spindleshaped
and
of
smaller
size than
the
tetra-
sporic
and
female conceptacles;
they
are about 250
,
long
and
140 /* broad.
They are formed in the uppermost joint of a branch;
the few antheridial filaments
I have seen
in the
form from
this
locality
have
all
been
short,
consisting
only
of
the
antheridial
joint
or,
besides,
of a
single vegetative
joint below.
While
I have
had
very few specimens growing upon
Turbi-
naria
at my
disposal,
I
have
collected
a
specimen
of
Zonaria
lobata at the shores
of St. Croix upon which numerous specimens
of
this
small Jania were
present
(Fig. 183).
Unfortunately the
exact
locality
of
this plant
is not known,
but most probably
it
13
Fig. 182.
Jania pumila Lamx.
Longitudinal
section
of
tetra-
sporic conceptacle of specimen
found upon
Turb.ina.ria.
(About 75:
1).
194
is from a more
sheltered
place.
Compared with
the
above
des-
cribed
specimens
these
are
comparatively
slender
with
longer
branches.
The
erect
filaments
are
several
times
dichotomously
branched.
The
antheridial
conceptacles
occur
in
the
ends
of
these long branches
as against the
often
sessile ones
in the form
described
above.
The
tetrasporic
conceptacles
(Fig.
183)
have
longer
horns consisting
of
4 joints
;
female
conceptacles
I have
not
seen.
As
to
the
anatomy,
the
cells
in
the
central
strand
are
of
about the same length
as those
in the nodes.
Fig.
183.
Jania pumila Lamx.
Specimen found upon Zonaria.
(About 20:1).
In referring this plant to Jania pumila
I may point out that
I
have
not been
able
to make
any
comparisons
with
original
material
; to
arrive at an exact determination this seems necessary,
the more
so,
as
the
original
description
is
very
poor
and the
accompanying figure
of no value
at
all.
The form KUTZING has
illustrated
differs
considerably
from my
plant.
In
naming my
plant /. pumila
I rely upon HAUCK'S description
; this is based upon
specimens
from Puerto-Rico
and
seems
to
agree
well
with my
plant.
HAUCK
does
not
mention how
far
he
has compared
his
plant with original material.
The plant from Jamaica distributed
in "Phycotheca Bor.-Am.",
no.
799 seems to come very near to
mine.
This plant has only been collected
a few times,
but
is most
probably a common epiphyte upon larger brown
algae.
195
St. Croix: Judith Fancy (upon Turbinaria trialata) and another gather-
ing from the same island without exactly known locality (upon Zonaria lobata).
Geogr. Distrib.:
West
Indies, Red Sea,
Indian Ocean,
Japan
etc.
2.
Jama adhaerens Lamx.
LAMOUROUX,
I. V. F.,
Histoire des polypiers coralligenes
flexibl.
vulg.
nommes Zoophytes,
Caen 1816,
p.
270.
ARESCHOUG,
J.
E.,
in
J. AGARDH,
Spec. Alg.,
vol.
II, pars
2,
p. 559.
KUTZING, F., Tab. phycol.,
vol. 8,
pi. 83,
figs,
g,
h.
The specimens
I have
referred
to
this
old
species
of LAMOU-
ROUX vary considerably with regard to
size,
length
of
joints
in
Fig.
184.
Jania adhaerens Lamx.
Habit of a specimen.
(About
7:1).
Fig.
185.
Jania
adhaerens
Lamx.
Upper ends of filaments showing the
regular dichotomy.
(About 20
: 1).
proportion to breadth etc., but nevertheless
it seems very natural
to me
to
take them
together,
as
transitional
links
are
found
between them and they, most probably, are nothing but variations
of the same plant due to
differences
in
habitat.
The plant grows upon
stones,
corals
or
similar substrata or
intertwisted among other Corallinacese,
e. g.
Amphiroa fragilissima
or
epiphytically upon
larger
algae,
especially
Digenia,
stems
of
Halimeda,
Avrainvillea
etc.
13*
196
When growing upon stones etc.
it forms small dense, roundish
tufts
upto
1
2 cms.
high, when
epiphytic
it
often
covers
the
host plants quite densely.
The thallus
is
slender
(Fig.
184).
In the
basal part
of more
vigorous plants
its diameter reaches about
100 rarely up
to 150
tu,
upwards
it grows thinner and
in
the uppermost
thin
filaments
the diameter reaches only a length of about 30
60
fj..
The thallus
is
repeatedly
dichotomously
ramified
(Figs.
184
185).
At
the
base
of the branches a node
is always found.
The distance bet-
ween
the ramification
is
of very
variable
length, now long and
now
short,
but, when
long,
the
thallus
is
divided by
nodes
in
nearly equally long
joints.
The length
of the joints
varies from
5
8 times
their breadth.
Fig.
186.
Jania adhaerens Lamx.
Basal parts
of filaments with
flat, roun-
dish attachment
discs.
(About 60
: 1).
The
cells
in
the nodes
are about 200
/j.
long and
1 p thick;
in
the
joints
3
5 rows
of
long
cells
are
mostly
found
;
these
have nearly the same length
as those found
in the nodes.
In the basal parts
of
the
thallus
I have found a few times
some small attachment
discs
(Fig. 186);
those
are mentioned by
YENDO
in
his paper:
"Corallinae verae Japonicae (Journ.
of
the
College
of Science,
vol.
16, part
2,
p. 24, Tokyo
1902).
Nearly
all the specimens
I have come across are sterile
; some
few tetrasporic specimens were found growing epiphytically upon
Digenia
(Fig.
187).
The
conceptacles
are
urnshaped
;
they
are
developed
from
the
basal
cell
in
the
upper
dichotomies
and
provided with two long branchlets often several times articulated.
The
conceptacles
are
about
300
fj.
long and
of
nearly the same
breadth.
197
In another specimen growing upon Corals some
few concep-
tacles were
also
found.
These were about 240^ broad and 340 //
long, and had very long horns.
As mentioned above
this
plant occurs both upon
stones
etc.
and
epiphytically upon larger algas.
It
is found both
in sheltered
Fig.
187.
Jania adhaerens Lamx.
Specimen with
tetrasporic conceptacles.
(About 20
: 1).
localities and
in more exposed
ones, and
in shallow
as well
as
in
deeper water (about
10 fathoms
or more).
It
is a very common species along the shores
of the islands.
Geogr. Distrib.
:
Red Sea, Indian Ocean, Japan.
3.
Jania decussato-dichotoma Yendo.
YENDO,
K., A revised
list
of Coralline
in Journal
of
the College
of
Science, Tokyo
1905,
vol. XX,
p.
37.
Corallina decussato-dichotoma Yendo, Corallinae verse Japonicae in Journ.
of the College
of Science.
Tokyo 1902,
vol. XVI,
p.
25,
pi.
Ill,
figs. 13;
pi. VII,
fig.
34.
Intermingled
with
other
Corallinaceae,
e.
g. Amphiroa
fragi-
lissima and
Corallina cubensis
I have
found
a
few specimens
of
198
a
somewhat more
robust
plant
than
the
aforementioned
one.
It seems
to show much
likeness
in
shape
and
size
to YENDO'S
species.
In the specimens found the diameter of the joints varies from
110^
to 175 [2,
their length being
3
5 times as
long.
The whole
plant
is rather straight and
stiff.
The
joints
in the filaments are cylindrical, except the upper-
most ones in the ends of the filaments which taper much upwards,
ending
in acute pointed summits.
The specimens found are
all
sterile.
I wish to point out that
they show much
likeness
to the
habit-figure
of KUTZING'S Jania
tenella in Tabulae Phycologica?,
vol. VIII,
pi.
85
(fig.
/),
but
this
species
is
smaller;
in
DE-TONI'S
Sylloge
the
filaments
are
said
to be 100^
broad.
The plant was collected in rather deep water, about 10 fathoms.
St. Jan:
off America
Hill
and
in
the
sound between
St. Jan
and
St. Thomas
off Cruz Bay.
Geogr. Distrib.
:
Japan.
4.
Jania
capillacea Harv.
HARVEY, W. H., Nereis Boreali-Americana, Part
II,
1853,
p.
84.
In the Herbarium of the Botanical Museum
is found an
old
specimen
of a Jania which
I think can be considered
as a form
of HARVEY'S
plant.
HARVEY'S
short
diagnosis
runs
verbally:
"minute,
dichoto-
mous,
capillary,
with wide
axils;
branches recurved,
squarrose;
articulations
cylindrical,
four to
six times
as long
as broad".
The plant
in
question
(Fig. 188)
agrees very well with
this
diagnosis with the exception that the
joints are somewhat shorter
in proportion to
their breadth, these being about 150^ long and
350400^ broad.
A plant very similar to that from
St. Croix has been
distri-
buted in Phycotheca Bor. Am.,
Nr. 150,
originating from Jamaica.
This
plant,
too,
has
comparatively
short
joints.
On
the other
hand
I have seen a small specimen belonging to the Riksmuseum,
Stockholm, which
seems
better
to
agree
with
the
diagnosis
of
HARVEY.
It
was
collected
at
Key West
and
determined
by
FARLOW.
The
filaments
in
this plant
are about 110 ^
thick,
the
length of the joints about 5 times as long, but this plant approach-
es considerably
to
some
of
the
forms
I
have
referred
to
Jania
adhaerens.
199
The
specimen
from
St.
Croix had
tetrasporic
conceptacles;
these were developed not only
in the uppermost joints below the
dichotomy,
but
also
farther down
in the
plant.
Perhaps we
in
this have a means
to
distinguish the two plants
in question,
in
any case
I have always found
the conceptacles
in the uppermost
joints
in
the
forms
I
have
referred
to
Jania
adhserens,
but
I
may point out that
I have seen only very few fruiting specimens.
Fig.
188.
Jania capillacea Harv.
Part of a
sterile plant and a branch with
tetrasporic conceptacles.
(About
15
:
1).
Unquestionally Jania capillacea comes near to Jania adhserens.
What especially distinguishes
it from this
species is the frequently
obtuse angles and the arch-shaped,
recurved, squarrose filaments.
St. Croix (without locality) Benzon.
Geogr. Distrib.:
West
Indies.
5.
Jania
spec.
On a
reef
in
the harbour
of
St. Thomas
I
have
collected a
few small
sterile pieces
of
a Jania which
perhaps
are
referable
to Jania rubens (L.) Lamx.
They
differ from the two preceding
species by
the
tapering
of
the
joints towards
the
ends,
these
being not
so markedly
cylindrical
as
is the case of these species.
The thicker joints
are about 150^
thick
and
2
3 times
as
long, the thinner about 80
90 //
thick.
200
III.
Ceramiales.
Fam.
1.
Ceramiacece.
Subfam.
1.
Spermothamnieae.
Spermothamnion Areschoug.
1.
Spcrmothaiuuion
investiens (Crouan) Vickprs.
VICKERS, A.,
Liste
cles Algues
marines de
la Barbade
(Ann.
sciences
nat., IX. ser.,
t.
I,
1905,
p. 64).
Fig.
189.
Spermothamnion
investiens (Crouan) Vickers
var.
cidaricola Bergs.
Base of a plant.
(About 175
:
1).
Callithamnion
investiens Crouan
in A. SCHRAMM
et H. MAZE,
Essai de
classification des Algues de
la Guadeloupe, Basse-Terre 1865,
p.
7.
var.
cidaricola Bergs.
BORGESEN,
F., Some new or
little known West Indian
Florideae (Bot.
Tidsskr.,
vol. 30,
1909,
p.
17).
201
This
beautifully purple-rose plant was found upon the pikes
of Eucidaris
tribuloides,
often
covering
these quite densely
;
the
tufts reach a height
of
1 l2 cm.
The basal creeping filaments
(Figs. 189, 190 A) are irregularly
branched;
they are
about 30 // broad,
having a very
thick wall
(often
8
10^
thick).
The filaments
are fastened
to the pikes of
the Echinoderm by means
of
rhizoids.
These
are
shorter
or
longer
without
any
transverse
walls,
but having very thick peripheral walls, the
lumen of the cells
is,
in this way, reduced
to
very
little.
At
the
bottom
end
the
rhizoids
for the most part broaden out to
a
flat, roundish,
irregularly lobed
disc.
The
erect filaments
are very
straight
and
not
much
branched
;
the
branches
issue alternatingly, but seldom oppositely.
The
filaments
are
from
16
25 ^
broad;
the
cells from
3
5 times
as
long
as the
diameter.
The
last
mentioned
contain
many
small,
oblong,
parietal
chromato-
phores
more
or
less
growing
together,
forming
irregularly
lobed,
parietal
plates
and having several
nuclei especially in the
apical
cell
where
often
more
than
ten
are to be found.
Only plants with tetra-
sporangia were found.
These
are
situated
terminally upon a short one-celled branchlet
growing out singly (very rarely in twos) from
the
upper
end
of
the
mother-cell
(Fig.
190 C).
Only
seldom
the
branchlet may
have two
cells;
sometimes,
too,
it has a
lateral
stalk-cell with
a sporangium
(Fig.
190 B).
The
sporangia
are
tetrahedrally
divided,
ovate
roundish,
about
46
52 //
long, and 44
46 // broad; the wall
of the
sporangia
is very thick,
6
S/j.
or more.
The original specimens upon which the
brothers CROUAN have based the description
of their species were
found upon Galaxaura lapidescens and Strombiis gigas.
In SCHRAMM
et MAZE, "Essai de
classification des Algues de
la Guadeloupe"
l
]
1
) During a stay in Paris
I saw this rare book in the library of Dr. BOR-
NET, and he allowed me to take a copy of
it.
Fig. 190. Spermothamnion
investiens (Crouan)
Vickers,
var.
cidaricola
Borgs. A, piece of a plant
with creeping and
erect
filaments (25:1); .Band
C,
pieces
of
erect
fila-
ments
with
tetraspores
(B, 50:1;
C,
70:1).
202
we
find the following description:
"Frondes
filiformes,
articulees,
monosiphoniees,
de couleur
rose carmine
se conservant
parfaite-
ment en herbier" and
for the variety: "Fronde filiforme,
articulee,
monosiphoniee,
beaucoup
plus longue
et plus
rigide que
1'espece
type, de coloration rose pale".
These
descriptions are very poor,
and any exact determination by means of them is excluded.
There-
fore
it has been
of much value to me, owing to the kindness
of
Mr. PAUL HARIOT
in
Paris, to be able to study an
original speci-
men belonging
to
the Museum
d'histoire
naturelle.
This
plant,
growing upon
Galaxaura,
in
nearly
every
respect
agreed
with
mine.
It had the same horizontal, creeping filaments
fixed to the
host plant with
similar rhizoids
as
in my plant, and from these
creeping filaments
the
erect ones grow up between those
of
the
host
plant.
But while the
erect filaments
in my plants are only
slightly
branched
and,
as
a
rule, only
in
their
upper part,
the
filaments
in
the
type
specimen
are
freely
branched
from
near
their base upwards.
As mentioned above my specimens
had only tetrasporangia,
and
this was also the case with
all the plants found on specimens
of
Eucidaris
tribuloides
collected
by
Dr. TH. MORTENSEN,
who
most kindly placed
his material
at my
disposal.
This
species
is
found
in
deeper water
only,
at
a
depth
of
abouth 15 fathoms.
It had
ripe tetrasporangia
in the month
of
March.
St. Jan: in the sea
to the north
of
this island.
Geogr. Distrib.
:
West
Indies.
Subfam.
2.
Griffithsieee.
Griffithsia C. Ag.
1.
Grifflthsia
globifera (Harv.)
J. Ag.
AGARDH, J.,
Epicrisis, 1876,
p.
67.
DE TONI, Sylloge Algarum,
vol. IV,
p. 1280.
BORGESEN,
F., Some new or
little known West Indian Florideaa II
(Bot.
Tidsskrift, vol.30,
1910,
p. 204).
Griffithsia corallina?
var.
globifera Harvey,
Nereis Bor.-Am.,
part
II,
p.
228,
tab. XXXV A.
Griffithsia globulifera (Harv. in litt.)
in KUTZING, Tabulae Phycologicae,
1862,
vol. XII,
p.
10,
tab.
30.
Griffithsia Bornetiana Farlow, The marine Algae of New England, p. 131,
pi. X,
fig.
4,
pi. XI,
figs.
3 and
5.
As to the
specific name
I
refer
to my remarks
in the paper
quoted above.
203
This
species
easily
known by
its characteristic
antheridial stands has
been
found
in
great
quantities
in
the
sea
around
Buck
Island
north
of
St.
Croix,
and
in
the
sound
between
St. Thomas and St. Jan.
In
the
North
Atlantic
it
is
known
from
the
shores
of
Massachusetts down to New
Jersey.
Here
it
is a sum-
mer plant, while in the West
Indies
it was found by me
in February
March.
It is almost certain that
it has not been
found
pre-
viously in the West
Indies.
To be sure M
lle ViCKERS
records
it
in
her
list
1
)
of
algae
from Barbadoes,
but,
as pointed out by LEWIS 2
),
Professor Farlow
does
not
believe
the
specimens
of
M lle VICKERS to be
identical
with Gr. Bornetiana.
More-
over Prof. FARLOW
himself,
most
kindly,
has
informed
me by
letter
that
he had
written
to
Dr. BORNET
on
the
subject
and,
that
the
latter
after having seen the
above-mentioned
specimens
found by M lle VICKERS
did
not think her warranted
in
naming them
Gr.
globifera.
In
the
above
quoted
paper of LEWIS, edited only
Fig.
191.
Griffithsia globifera
(Harv.)
J.
Ag.
a, basal part of a plant and upper
end
of
a
branch,
b,
part
of
a
female
plant with cystocarps surrounded by pro-
tecting
cells,
verticillate
ramified
hairs
and dwarf shoots,
(a, about 6:1;
b, about
18:1).
!
) VICKERS,
A., Liste des algues marines de
la Barbade.
(Ann.
Sc. Nat.
9e
s6rie, Bot.
t.
I,
1905).
2
) LEWIS,
I. F., The
life history
of Griffithsia Bornetiana (Annals of Bo-
tany,
vol. XXIII,
nr. XCII, Oct.
1909).
204
a few years ago, we have got a
detailed
description of this plant
to which
I
refer,
restricting
myself
here
to
a
short
description
only and some
figures
of
the West
Indian
plant,
showing
its
great likeness to and
small
differences from
the North American
form.
The
chief
difference
is
that the
cells
in the West Indian
plants generally are much thicker than those of
the
plants from
the North
Atlantic.
This
applies
especially
to
the
cells
in
the
basal part
of the thallus.
In the West
Indian form the
cells are
nearly
oval
about 2mm.
long and 1,3mm.
broad, while
in
the
North Atlantic plant the cells are much thinner, but on the other
hand much longer, nearly cylindrical with somewhat swollen upper
ends.
Higher up
in
the
thallus
of
the West Indian plants the
cells
are
often
nearly
spherical,
of
very variable
size,
the larger
about
1,4 mm.
broad.
Compared
to
the
sizes
given by LEWIS,
1.
c.
p.
642,
it
is
evident
that
the
cells
of
the West Indian form
are
larger
and
also
seem
to have
a somewhat
different
shape
from
the North
Atlantic one, but
I do not think we can lay so very much stress
upon
this
fact,
and Professor FARLOW
has
also most
kindly
in-
formed me that the shape and
size of the North American plant
vary very much, especially in the tetrasporic and sterile specimens,
and
as my plant, on the other hand,
in its tetraspores, antheridia
and
cystocarps,
seems
to
agree
completely with
the
description
of
that
from the United
States
I
have
referred
it
without any
doubt to
this
species.
The
West
Indian
plant
forms
dense,
semiglobular
tufts,
reaching a height of
6 cms. or more.
It grows especially epiphyti-
cally upon
calcareous
algee,
e.
g. Halimeda,
Penicillus
etc., but is
also found upon
stones and
pieces
of coral
at the bottom
of the
sea.
The plant is fastened to the substratum by means of vigorous
rhizoids
(Fig.
191 a)
1
).
These
grow
out
from
the
basal
cells,
having very thick walls and being very irregularly ramified.
Also
from the basal end
of
the
cells
in
the lowest part
of
the plant
rhizoids grow
out,
but
they are
shorter
here
and
not
ramified.
They grow downwards, attaching themselves to the upper end of
the
cell
below,
contributing in
this way to
the strengthening of
the whole
thallus
(Fig. 191 a}.
The wall
of the
cells
in the basal
part are very thick and
stratified.
The
thallus
is
repeatedly
forked
(Fig. 191 a)
and,
judging
from
the young
stages
of
division
I
have
seen,
the
division
l
) LEWIS,
J. c.
p. 653 points out that Griffithsia
is anchored to the substra-
tum either by a special attaching disc, or by a tangled mass of rhizoids.
205
often
comes
very
near
to
true
dichotomy,
but
when
exam-
ined
more
carefully
one
finds
that
one
of
the
young
cells
is
always
formed
a
little
earlier
and
is
larger
than
the
other
(comp.
Fig.
192
c,
d).
LEWIS,
too,
(1.
c.
p.
250)
considers
the
ramification to be lateral, "true dichotomy appears never to occur".
In
Griffithsia
corallina
KYLIN
:
)
found
the
ramification
to
be
lateral, and OLTMANNS
says
in Handbuch the same
for Griffithsia
on the whole.
As pointed out by LEWIS, and according to my material also,
by
far
the
greater
part
of the specimens were
tetrasporic.
The
tetrasporangia
form
a
ring
at the upper end
of the
cell (Fig. 192 a).
As a rule three of them
are found together, one
of them placed termin-
ally,
the
others
later-
ally upon
a basal
cell
(Fig.
193
a,
d)
;
the
development
of
this
tetrasporic
branch
is
given by LEWIS.
On the outside this
tetrasporic ring
is pro-
tected by
a
circle
of
short, thick somew^hat
inwardly
curved
cells,
together forming a kind
of
involucrum
(Fig.
192 a).
As pointed out
by
LEWIS
these
cells
..
Fig.
192.
Griffithsia globifera
(Harv.)
J. Ag.
grow
up
immediately
a> part O f a tetrasporic plant,
b,
a dwarf shoot,
from
the
cells
in
the
c a
d
d> upper ends of main filaments showing
ramification,
(a, about 25
: 1
;
b, about 250
: 1);
main
filaments
(Fig.
c and
r/, about 30 :1).
193 a).
In
Griffithsia
corallina KYLIN
(1.
c.,
p.
116),
on
the other hand,
describes and
beautifully delineates the protecting cells as excrescences from the
basal
cell
in
the
tetrasporic
branch.
A
cell
is cut
off from the
basal
cell,
and
this
cell
is divided
into two
cells,
the uppermost
being very
enlarged
and
becoming
a protecting
cell.
This \vay
:
)' KYLIN, H., Die Entwicklungsgeschichte von Griffithsia corallina (Lightf.)
Ag.
(Zeitschr.
f. Botanik,
8.
Jahrg.,
1916,
p.
99).
206
of development
being
rather
different
from what
is
the
case
in
GriffitJisia globifera
I
again examined my
material,
and
I
found
that
it verified
the observation made by LEWIS.
Fig. 193 b and
c
shows two young
protecting
cells.
They grow
out
from
the
mother-cell
in
a
precisely
similar method
to
the
basal
cells
in
the
tetrasporic
branch.
LEWIS
describes
it
in
this way
(1.
c.,
Fig.
193.
Griffithsia globifera (Harv.)
J.
Ag.
a,
base and top
of two
cells
of tetrasporic plant showing the large porus
; upon the lowermost
cell two
tetrasporic branches and
two
involucral
cells,
b and
c, young
involucral
cells,
e,
involucral
cell
with
swollen
base,
d, young
telrasporic
branch.
f, young cystocarp with involucral cells,
(a, about 80
: 3, b
f, about 150: 1).
p.
664):
"On
the
side
toward
the
stalk-cell
the
cytoplasm
of
the mother-cell
is produced
into
a
rather narrow
strand, which
meets a
similar strand from the
stalk-cell at the point where the
callus-like plugs are developed".
A few times
I have
found the
basal narrow
strand somewhat
swollen
(Fig.
193 e),
but
I have
207
not seen
any
wall
or pore
so
it
is
evidently
nothing
else
but
an accidental
swelling.
According
to
KYLIN'S
detailed
examination
of Gr.
corallina
the present
species,
with regard
to the development
of the pro-
carp
etc.,
differs somewhat
from Gr.
corallina making a revision
desirable.
As pointed out
by KYLIN the
chief difference
is that
the
cell
supporting
the
carpogonial branch
in Gr.
corallina cuts
off another cell,
this being the auxiliary one, while
in Gr. globifera
no such
cell
is
cut
off,
the
supporting
cell
itself acting
as the
auxiliary
cell.
Unfortunately my material
is now unfit
for more
detailed
examination
having
been
kept
in
formalin
for
more
than ten years, but my
figure
of the procarp, published
in
1910
(1. c., fig. 20 E
1
), seems to agree precisely with the figures in LEWIS'S
treatise and
seems
to
verify
his
description.
But.
of course, an
examination
of
fresh material would be
desirable.
Fig. 193
/
shows
a young
cystocarp
in which
the
peculiar
fusion
of the cells
in the centre of the female branchlet has taken
place.
From the
large placental
cell,
resulting from
this
fusion,
two
sporogenous
lobes
are
developed.
The
figure
shows
the
involucral
cells
as the
enlarged end-cells of the two-celled branch-
lets issued from the basal
cell
in the procarp.
Before
the
examination
of
LEWIS
the
development
of
the
cystocarp
in
Griffithsia globifera
has
been
examined
by FARLOW
(1.
c.), SPAIDING
1
) and Miss A. SMITH
S
).
Fig. 20 D
in my
earlier description
of
the plant
shows one
of the large terminal
cells
of the male plant with the
characteri-
stic
cap-like disc of antheridia
at the summit of the
cell.
FARLOW
is the
first who
has described
it and given a figure
of
it
;
later
it has
also been mentioned by LEWIS.
In the West
Indies
I have found
this
species
fully developed
with
tetraspores,
antheridia
and
cystocarps
in
the months
of
February
arid March.
All the specimens were collected
in rather deep
sea in depths
from
5
15
fathoms
with
the
exception
of
a
single
specimen
gathered
during my
first
visit
to
the West
Indies
in
1892.
It
was
found
in
the
environs
of
Christianssted,
St.
Croix,
most
probably washed
ashore.
l
) SPALDING, V.
M., Development of the sporocarp
of Griffithsia Borne-
tiana (Proced. Am. Assoc. Adv. Science 39;
1890).
a
) SMITH, A. A., The development of the cystocarp
of Griffithsia Borne-
tiana.
Bot. Gazette, XXII
1896.
208
This species has been found near Buch Island at
St. Croix in
a depth
of about
5 fathoms
and
in
several
places
in
the sound between St. Jan
and St. Thomas.
Geogr. Distrib.
:
The Atlantic coast of North America.
4.
Griffithsia
spec.
A
single specimen
of
a
sterile plant,
which
I suppose
to be
a Griffiihsia, has been dredged
in the sound between
St. Thomas
and
St.
Jan,
off Cruz Bay.
The thallus
of
this plant
is repeatedly pseudodichotomously
ramified, and has
in the basal part large, nearly cylindrical
cells,
about
300
400 /j.
thick
and
7
8 times
as
long.
Towards
the
summit the filaments taper gradually, the
cells at the same time
becoming shorter; the uppermost cells are only about 150
tj. thick,
the top
cell, when more developed, about 100 u
only.
It was found
in a depth
of about
20 meters.
Subfam.
3.
Mesothamnieae.
Mesothamnion nov. gen.
Habitus
frondis
omnino Callithamnio
similis,
tetrasporangiis
etiam
eodem modo
dispositis
et
divisis
;
differt autem
ab
hoc
genere corpusculis
antheridiorum subcylindricis
pedicellatisque
et
procarpiis terminalibus
cellulis
auxiliaribus
singulis
instructis.
Cystocarpia ex corpusculis
5
6 subglobosis,
carposporas con-
tinentibus, composita,
ramulis pluribus
plus minusve involucrata.
Mesothamnion caribaeum nov.
spec.
Planta
in
parte
basali
rhizoideis
numerosis
ramosis
affixa;
caule non
corticate quoqueversum
lateraliter ramoso,
cellulis fere
cylindricis
in
media
parte
ca. 450^
longis,
230 u
latis.
Kami
eodem modo ramulos
gerunt, ramulis pseudodichotomis ex
cellulis
cylindricis
in
media
parte
ca.
80 p.
longis,
25
ij.
latis
compositis.
Tetrasporangia
sphaerica triangule
divisa, 45
it
lata.
Corpuscula antheridiorum
subcylindrica,
pedicellata,
ca.
75
IJL
longa,
40 //
lata.
Cystocarpia
satis magna ex pluribus corpusculis
plus minusve
sphsericis
et
magnitudine
diversis composita
sunt.
The
thallus
grows
like
a small
shrublike
tuft
about
2 cm.
high.
It
is fastened
to the host plant by means
of a very rami-
fied root-system
(Fig. 194 d).
This
consists, not only
of the basal
ramified end
of
the main filament,
but
also
of
several vigorous
20'J
filaments emerging higher up from the main stem.
Like the main
stem
these
filaments
end
in
rhizoids
often growing
together to
small
discs.
Fig.
194.
Mesothamnion caribaeum nov. spec,
a
c, quite young and older
cells showing shape
of chromatopnores.
d, base of a plant.
(a,
b,
c, about 200:1;
d, about
40).
The basal
cells
in
the
main
stem
are comparatively
small,
but they rapidly increase
in
size,
so that,
at a short distance from
the
base, we
find
the thickest part
of
the main stem,
the
cells
here reaching
a
breadth
of
250
[j.
or
even
more
;
on
the other
14
210
hand,
the
cells
in
this part
of
the stem
are mostly short
ones,
often
reaching
only
a
length
of
about
100 /*.
From
this place
the
cells
gradually
taper
upwards,
becoming
at
the
same
time
longer.
In the middle
of a
plant the
cells
are about 450 p. long
and 230
j
broad; they are nearly
cylindrical, yet somewhat swol-
Fig.
195.
Mesothamnion caribaeuin nov. spec,
a, part
of tetrasporic plant.
b, part
of a female plant,
(a, about 40:1;
b, about 50:1).
len at the base,
tapering upwards
and
again
a
little thicker at
their upper end.
Near the summit of a branch in active growth the cells in the
main filaments are almost quadratic, about
15 //
broad.
In some
plants a main stem can be followed through the whole length of
211
the plant,
in others
this
is not the
case
as
several branches
are
nearly equally vigorous.
No
cortical layer
is found,
but
from
the
basal
cells
of
the
more vigorous branches a
rhizoid-like filament often emerges (Fig.
194 d),
growing
downwards
along
the main stem,
but generally
not
attached
to
it.
In
the
lowermost
part
of
the
plant,
as
mentioned above,
these
rhizoids
reach down
to
the
host plant
and
fasten themselves
to
it,
but higher up
it may happen that
they attach themselves to
a branch beneath them.
Fig.
196.
Mesothamnion
caribaeum
nov.
spec,
a,
part
of
an
antheridial
plant,
b, antherial stands,
c
h, development of antheridial stand.
(a, about 50:1;
b, about 125:1;
c
g, about 300:1;
h, about 450:1).
The plant
is much ramified
(Fig.
195),
the
branches issuing
multilaterally
to
all
sides.
As
mentioned
above
some
of
the
branches grow
out vigorously
like
the main stem,
but
most
of
them are not
so much developed.
These smaller branches are in
the same way multilaterally ramified, bearing repeatedly pseudo-
dichotomously
ramified
branchlets
on
all
sides.
The
branchlets
are longest
at the base
of
the
branches,
higher up
shorter and
at the same
time
bent upwards,
the whole
branch
in
this way
14*
212
often
getting
a
penicilliform
appearance.
The
cells
in
these
branchlets
are
nearly
cylindrical,
being
in
the
middle
of
the
branchlet about
80 // long and
25 // broad.
The chromatophores
(Fig. 194 a,
b,
c)
are
parietal,
consisting,
in the
quite young
cells,
of
shorter or
longer irregularly shaped
plates
;
in more developed
cells they have
the shape
of a small
roundish
disc and
finally
in
the
old
mature
cells we
find them
like
the
thin,
sinuate
ribbons
generally
found
in
this
group
of
algae.
One
nucleus
is
present
in
each
cell.
Hairs
are
wanting;
at
least
I have
not
found any
in my material.
Male
(Fig. 196)
and
female
(Fig.
] 95 b)
plants
as
well
as
tetrasporic
plants
(Fig. 195 a)
occurred
in the collection.
Jud-
ging by
the
rather
scarce ma-
terial
at
hand
the
tetrasporic
and the
female
plants
are
the
most vigorously developed
and
also
most
common,
while
the
antheridial
plants
seem
to
be
more
slender and
rare.
The tetrasporangia (Fig. 195
a) are spherical, lining the upper
(inner)
side
of
the
filaments
in
Fig.
197.
Mesothamnion
caribaeum
the branchlets, issuing singly at
nov.
spec.
Two
procarps
with
tri-
the
upper
end
of
each
joint.
chogynes.
a, with adherent sperma-
,.
J
.
,
tium.
(About 200
: 1).
They are tetrahedrally divided.
Their diameter reaches a length
of about 45 /i;
their wall
is about
2,5^
thick.
The antheridial stands (Fig. 196) are pedicellate,
subcylindric-
al bodies
about
75 //
long
and
40 //
broad;
the
stalk
is
about
30^ long and
12
/j. broad.
They are
found
in
the same places
as
the
tetrasporangia,
lining
the
upper
side
of
the
filaments.
They originate from a cell which
is richly
filled with protoplasm.
This
cell
is
divided
by
transverse
walls
into
3
4
superposed
cells
(Fig. 196 c).
These increase
in
size
and, with the exception
of the
lower
part
of
the
basal
cell
which
forms
the
stalk,
are
divided
gradually
by
several
anticlinal
and
periclinal
or more
213
Fig.
198.
Mesothamnion
caribaeum
nov.
spec.
Development
of cystocarps.
a,
the
auxiliary
cell
is divided
in three
cells,
b,
more advanced stage.
(A.bout 200:1).
irregularly arranged walls in a number of small
cells or rather short
filaments, the end cells of which are the antheridia (Figs. 196 d
h).
The
procarp
occurs
terminally
upon
short
branchlets
(Fig.
195
6).
When
fully
developed
it
(Fig.
197)
consists
of
a
basal
cell
from which the
carpogonial
branch
issues,
and
a
sterile
cell
nearly
opposite
to
it
;
in
the
middle we
find
the
large
auxiliary cell and above it
a
sterile
apical
cell.
The
carpogonial branch
is com-
posed
of
3
cells and
the
carpogonium
with
the
trichogyne
;
the
last men-
tioned
is
rather
robust,
nearly cylindrical and very persistent.
By means
of
staining in
MAYER'S hsemalum
I
have
been
able
to
see
the nucleus
clearly
as
well
in the auxiliary
cell
as
in the other ones
of
the procarp
except
in
the
carpogonium,
this
most
probably
being
due
to
the
bad
preservation
of
the
material,
this
having
been
kept
in
rather
weak
spirit.
After the fertilization the auxili-
ary
cell increases
in
size, and soon
two cells are cut off, one at both ends
of
it
(Fig. 198 a).
These
cells again
are divided
into smaller ones
(Fig.
198 b).
Not having had
sufficient mate-
rial
I have not been able to
follow
the
development
in
detail, but the
result
of the
further growth
is
that
we
get a
large cystocarp composed
of several larger and smaller round-
ish
bodies
consisting
of the nume-
rous carpospores
(Figs. 199
and
200).
Of
these
bodies
the two
on each
side
are
the
largest;
so
far
I have been able
to
follow
Fig.
199.
Mesothamnion
cari-
baeum nov. spec.
Young cysto-
carp,
the trichogyne
is yet pre-
sent.
(About 120:1).
214
the evolution
these
originate
from
the two
cells
firstly
cut
off
from the auxiliary cell.
But besides these two larger balls several
of variable
size are present, these most probably originating from
divisions
of the cell found
in the middle
after the division
of the
auxiliary
cell.
Immediately
after the
fertilization
several filaments begin to
grow out from
the upper end
of
the
cell which
carries
the pro-
carp.
These filaments
are branched
several
times and surround
the cystocarp forming
in
this way
a kind
of
involucrum
round
it
(Figs.
199 and
200).
Fig.
200.
Mesothamnion caribaeum nov.
spec.
Nearly ripe cystocarp.
(About 40
:
1).
If we now seek
as to which
of the other genera belonging to
the
Ceramiacese
our
plant
is
most
closely
related
it
is
evident
from
the
description and
figures
above
that,
in the vegetative
formation of the thallus,
it comes very near to Callithamnion.
The
base
of the plant, the
ramification
of the
thallus,
the chromato-
phores and the habit
of the thallus on the whole agree perfectly
well with that genus and the distribution
of
the
tetrasporangia,
too,
is
quite
the same
as
that found
in Callithamnion.
On the
other hand, with regard to the
antheridial stands
and
especially
the
building
of
the
procarp
and
cystocarp,
it
differs decidedly
from
that
genus.
As
to
these
organs
it
seems
to me that we
215
find the most closely related forms in the group of Spermothamniess.
In
this group,
as
in the case
of our plant, the procarp
is termi-
nally placed and
after
the
fertilization the cystocarp
is more or
less covered by filaments
in a similar way
as in our plant.
Judg-
ing by the
figure
of Ptilothamnion Pluma given by BORNET
x
) the
procarp
in
this plant seems to be exactly like that in the present
one.
In other genera,
e. g. Spermothamnion we have two
auxili-
ary
cells;
but,
if we consider
the
halfpart
to
the
right
of
the
schematic
figure of the procarp of
this genus given by OLTMANNS'
in Handbuch,
p. 705,
it
is
easily
seen
that
this
is
exactly
like
the procarp
in our plant.
As to the antheridial stands these, too, show likeness to those
found
in
the
same group;
comp.,
e.
g., the figure
2
of Spermo-
thamnion flabellatum Born, given by BORNET et THURET,
1. c.,
pi. 8.
Closely resembling
the
antheridial stands
of
our plant
are those
found
in
Antithamnion
Plumula
judging
from
the
figure
ol
BUFFHAM
2
). Much alike too, are, the antheridial stands of Compso-
thamnion gracillimum
as
represented by
the same
author 3
).
In
Cattithamnion,
on the other hand,
the
antheridial
stands mostly
form small
cushions
like those
I have
described and
figured
for
Callithamnion cordatum;
for Calliihamnion byssoides BUFFHAM has
figured
(1.
c.,
1884,
pi. X,
fig.
5)
the
antheridial
stands
of
this
plant,
these showing very great
likeness to the present
one, but
the West Indian specimens
of
C.
byssoides
found by me had the
low,
cushion-like,
antheridial
stands commonly
found
in
Calli-
thamnion.
In ENGLER und PRANTL,
Die Natiirl. Pflanzenfamilien,
I. Teil,
Abt.
2
the
Fam.
Ceramiaceee
is
divided
in
15 groups;
it
seems
to me on account
of
the above mentioned
facts
that our
plant
must be considered
as the representative of a new group
: Meso-
thamniese forming an intermediate
link between the groups
Calli-
thamniese and Spermothamniese.
Mlle VICKERS
in her "Liste des Algues mar.
de
la Barbade"
(Ann.
sc.
nat.
Bot.
1905,
p. 65)
mentions
a "Cattithamnion?
sp.
nov. ? A des
antheridies cylindriques, comme
les Pleonosporium,
mais
les sporanges ne renferment que quatre
spores en tetraedres.
J
) BORNET,
E.
et G. THURET, Notes algologiques,
p.
179,
pi. 46,
fig.
1.
2
) BUFFHAM,
T.
H.,
Notes
on
the
Floridese and on some
newly-found
Antheridia (Journ. Queckett Microscop.
Club,
vol.
I,
Ser.
II,
1884,
pi.
XI,
fig.
2).
3
) BUFFHAM,
T. H., Notes on some
Florideae (Journ. Queckett Microscop.
Club,
vol. VI,
ser.
II,
1896,
pi. X,
fig. 1213).
216
Je
n'ai pas vu
de
cystocarpes".
Perhaps she has had the
pre-
sent plant before
her.
The
plant was dredged
in deep water
in
a depth
of
about
30 meters.
St. Jan:
Off Annaberg.
Subt'am.
4.
Callithamnieae.
Callithamnion Lyngb.
1.
Callithaninioii cordalum B0rgs.
B0RGESEN,
F., Some new or
little known West Indian
Florideee
(Bot,
Tidsskrift,
vol. 30,
1909,
p. 10).
This plant
is an epiphyte forming small,
rosy, shrub-like
tufts
upon the host plant.
It
is
not
corticated;
however,
from
the
basal
cells
of
the
vigorous
branches
in
the
lower-most
part
of
the
thallus
a
single
long
rhizoid
is
often
developed.
It
grows
downwards along
the wall
of
the
large
cells
in the
main stem
(Fig.
201).
These
rhizoids
are composed
of
nearly
cylindrical
cells
about
150 //
long
and
25 y.
broad.
The
frond reaches
a height from
2
4 cm.
; the
main
stem
is
at
the
bottom
part
nearly
straight
with
few
branches,
becoming
more
flexuous
and
richly
ramified
higher
up;
near
the
top
the main
axis disappears
(Fig.
202).
The
base
(Fig. 203 A]
consists
of
short
cells,
their walls often reaching a thickness of 18 // or more,
the diameter of the whole
cell measuring about 200 p.
From
the
cells
near
the
base rhizoids grow down-
wards and
assist
in
fixing the
plant.
Higher up
in
the main
stems
the
cells
grow
longer becoming at
the same time thinner,
at
first
twice
as long as broad
(long.
cell.
=
= 300^;
lat.
cell.
160//),
and
then
nearer
the
top 58 times
as
long as broad
(long.
cell.
=
= 400 /r,
lat.
cell.
=
= 50/u).
The uppermost branches are much thinner, only
8/z
thick; they
are often arch-shaped and
bent
inwardly
(Fig.
204).
The ramification is alternate, in the upper part subdichotomous.
In my previous
description
I have
said that
hairs,
as a rule,
are absent;
this
is the
case,
too,
in the
older part of the thallus
:
Fig.
201.
Callitham-
nion
corda-
tum
B0rgs.
Rhizoid
growing out
from base
of a branch.
(About
170
: 1).
217
where
hairs
seldom
occur.
On
the
other
hand,
in
the
young
summits
of
the plant
being
in
active
growth
I have now by
a
renewed examination
of the plant found
hairs
in the ends of the
filaments.
The
hairs
are
about
3 p.
broad and
150
jj.
long.
The sporangia are obovate-oblong,
tetrahedrally divided
(Fig. 203 C, D]
;
they
are
sessile
and
occur
on
the
uppermost
and
inward
side
of
the
Fig. 203.
Callithamnion cordatum Borgs.
A,
base'
of
a
plant
(25:1).
B,
end
of filament with
hair (100:1).
C, part
of
tetrasporic
plant
(50:1).
D,
tetra-
spore
(150:1).
E,
part
of
antheridial
plant
(60
: 1).
F,
cell with
antheridial
stand (150
: 1).
G, cystocarp (60
: 1).
H,
young
procarp
(150:1).
/,
older
pro-
carp
with
fully
developed
trichogyne
(150:1).
K,
transverse
section
of
a
cystocarp
(60
:
1).
Fig.
202.
Callithamnion
cor-
datum Bergs.
Habit
of
a
fe-
male
plant.
(About 60
:
1).
mother-cell.
They
are
found
in
special
individuals,
but
a
few
scattered tetrasporangia can also occur
in the female plants (Fig.
204).
The tetrasporangia
are about 40 // long and
27 // broad.
218
The antheridial stands
(Fig. 203 E, F)
are found
at the same
places as the tetrasporangia;
they consist
of
a system
of closely
placed, short branches, of which
each bears
2
4 antheridia.
The
cystocarps
(Figs.
202,
203 G, 204)
are binate and trilo-
bed heart-shaped, sometimes also
more
irregularly
formed.
The
younger and smaller ones consist
only
of a
single layer of carpo-
spores
(Fig. 203 K),
but
in the
bigger cystocarps and especially
in the more
irregularly
shaped
several
layers
are
also
present.
The
carpogonial
branch
is
four-celled and possesses a very
long trichogyne
(Fig. 203 /).
Fig.
204.
Callithamnion
cordatum
Borgs.
Branch with cystocarps and
a single tetrasporangium (50:1).
The plant occurred as a com-
mon
epiphyte
on
Gracilaria
Blodgetti
and
was
found
only
in deeper water
(about
15
fat-
homs).
It was collected with tetraspores, antheridia and cystocarps
in the month
of March.
Occurred in many places in the sound between St. Thomas and St.
Jan:
off Cruz Bay.
Geogr. Distrib.
: Hitherto found only in the above mentioned locality.
2.
Callithamnion byssoides Arn.
ARNOTT
in HOOKER, English
Flora,
vol.
II, part
1,
1833,
p. 342
(Algae
by HARVEY).
HARVEY, Manual,
1849,
p.
178; Phycol.
Brit.
pi. 262.
ARE-
SCHOUGH,
I.
E.,
Phyceae
Scandin. Marinae,
1850,
p.
107,
pi. V,
B.
Cfr.
SCHMITZ, FR., in Berichte d. deutsch. bot. Ges., Bd. XI, 1893,
p. 280. BORGE-
SEN,
F., Some new
or
little known West Indian
Florideae
(Bot.
Tidsskr.,'
vol.
30,
1909,
p.
11).
Regarding a comparison
of the West Indian form with plants
from other countries
I
refer
to my remarks,
1.
c.
Here
I
shall
restrict myself
to
give a short description only
of
the West
In-
dian plant
(Fig.
205).
It
has
a
rather
vigorous main
stem whose
cells
are about
3
4 times
as long as
broad
(lat.
cell.
=
140//);
higher up the
cells grow thinner and thinner, the youngest
tips of the branches
being only
9
10 //
thick.
The branches emerge
spirally from the
219
main stem
; below, the side-branches grow out to long filaments like
the main stem
;
higher up
they
are
shorter
;
in
the
uppermost
part the ramification
is subdichotomous.
The plant
is not
corti-
cated and
hairs do not
occur.
The tetrasporangia are generally tetrahedrally divided, though
cruciately divided ones occur too
(Fig. 206 A).
They are
sessile,
oblique-obovate or nearly roundish when
ripe and 35
40^ broad.
The
cystocarps
are,
when
fully developed, irregularly lobed,
binate.
I
have
only
found
a
few
procarps
;
from
these
it
seems
evident
that
the carpo-
gonial branch is four-celled
; the
carpogonium has
a rather long
trichogyne
(Fig. 206 C).
Antheridial plants had not
been
seen
when
I
previously
examined the plant
; these have
now
been
found
by
renewed
examination
(Fig.
207).
The
antheridial stands occur
in the
same
places
as
the
tetraspor-
angia,
lining
the upper
(inner)
side
of
the
filaments.
Often
they
are
found
only
at
the
summit
of the
cells,
sometimes
they
occupy
nearly
the
whole
upper
side
of these.
They con-
sist of a system of short branch-
Fig. 205. Callithamnion byssoides Am.
Part of a
tetrasporic plant.
(About 60
:
1).
lets
in
which
the
uppermost
cells
are
the
antheridia.
The
antheridial
stands
in the West
Indian plant
differ rather much from those figured by BuFFHAM
1
).
In
his specimens these have a
single
short
axis while in the West
Indian plant, as mentioned above, the antheridial stand is composed
of
several short branchlets.
The tetrasporangia, cystocarps and
antheridia occur
in sepa-
rate plants.
The chromatophores
are
parietal
and
consist
of
shorter
or
*) BUFFHAM,
T.
H.,
Notes
on
the
Florideae and
on
some
newly-found
Antheridia (Journ. of the Queckett Microsc. Club,
vol.
I,
Ser.
II,
1884,
p.
341,
pi. X,
figs.
4,
5).
220
longer,
in the young
cells rather broad
(Fig. 206 B),
in the older
cells narrower,
irregularly sinuate ribbons
(Fig. 206 F).
Each
cell
Fig.
206.
Callithamnion byssoides Am.
A, B, branches with
tetraspores
(75:1),
(150:1).
C,
carpogonial
branch
with trichogyne (160:1).
D, young cystocarp (160:
1).
E,
older cystocarp
(75:1).
F,
cell with chromatophore (75:1).
contains a single nucleus (Fig. 206 B), but I wish to point out that
I
have not succeeded in seeing the nucleus in the older and larger cells.
The plant was
found with
cystocarps,
anthe-
ridia and tetrasporangia in the months of January
and February.
It occurred
in shallow water,
in a
sheltered place upon
the
roots
of
the mangroves
or upon other
alga3 growing
here.
St. Croix: The Lagoon
of Christiansted.
Geogr.
Distrib.:
Atlantic
coast
of
Europe
and
North Africa, Mediterranean Sea, Atlantic coast of North
America, West
Indies
etc.
3.
Callithamnion
spec.
This plant being quite sterile (only once a speci-
men was found with a few nearly
ripe tetraspor-
Fig
207.
angia)
I have not been able to determine it exactly,
Callithamnion
'
=>
'
byssoides Am.
but
as
it was
found
abundantly
in
some places
Antheridial
m
^ eep water
j
j ust want
to give a short
des-
{About 350
:
l).
cription
of
it and a few
figures too
(Fig.
208).
221
The plant grows
epiphytically
upon
larger
algae,
e.
g. Hali-
meda,
Udotea,
Avrainvillea and
forms entangled masses together
with Cladophora
crispula,
Cladophoropsis
etc.
It
is
fastened
to
the host plants by means
of rhizoids growing out from the
cells
in the main
filaments,
often
rather
high
up
in the plants (Fig. 208
b)
; the primary base
I
have
not
seen.
The
rhizoids end
in
small,
irregularly shaped discs.
The plant
has no
cortical
layer.
The
cells
in
the main
fila-
ments are nearly cylin-
drical
about
2,5 mm.
long and 400 ^ broad.
The
ramification
is
multilateral
or
alter-
nate, in the upper part
of
the
thallus
often
secund.
A few
of the
branches grow
out
as
filaments like the main
filaments, but most of
them
become
shorter
branchlets with definite
growth
; these branch-
lets
are
repeatedly
pseudodichotomously
ramified,
having
very
long
cylindrical
cells
often reaching a length
of 3 mm. or even more,
while
their
breadth
is
only about 100 p..
The few tetraspor-
angia found were tetrahedrally
divided.
Found
in a depth
of about 1012 meters.
St. Thomas: In the sea
to the west
of Water Island where
in many
places
it occurred in large
quantities.
Fig.
208.
Callithamnion
spec,
a, upper end
of
a
plant,
b, part of a filament with rhizoids.
(About 40
: 1).
222
Seirospora Harvey.
Seirospora
occidentalis
B0rgs.
BORGESEN,
F., Some new or
little known West Indian Floridese (Bot.
Tidsskr.
vol.
30,
1909,
p.
14).
This interesting plant (Fig. 209) was found among the above-
mentioned Callithamnion cordatum as an epiphyte upon Gracilaria
Blodgettii.
Fig.
209.
Seirospora occidentalis Borgs.
Part
of a female
plant.
(About
70: 1).
The plant
is much ramified
and forms
small,
dense
bushes
about
1
2 cm.
high.
The main stem
is
fastened
to
the
host
plant by means
of
short,
thick-walled
rhizoids
emerging from
the
lowermost
cells
(Fig. 210
^4.).
The
cells
found
here
are
short,
nearly
as
long
as
broad,
about
200 //
thick having
very
thick
walls
(the wall
ca.
40
fjt
thick).
223
Higher up in the stem
the cells grow evenly, thin-
ner
in
the middle
of the
plant
about
85 p
thick,
becoming at the same time
more thin-walled and long-
er
(4
5
times
as long
as
broad), decreasing in thick-
ness
evenly
towards
the
apex,
the
ultimate
cells
being
only
8
11 p.
thick.
These often, but not always,
end
in
a
thin hair (Figs.
210 Z>, 2114).
Breadth of
the
hair about 3^.
The plant is not corti-
cated.
It
is
richly
rami-
fied
on
all
sides,
in
the
uppermost
part
subdicho-
tomously.
Both the younger and
older
cells have
only a
single
nucleus
(Fig.
210 B, F),
in
accor-
dance with the
description
of ScHMixz
1
).
The
parietal chromato-
Fig.
210.
Seirospora occidentalis B0rgs.
A,
base
of
a
plant
(25
: 1).
B
and
C,
branches with tetraspores (60
: 1). D, branch
with
antheridia
(60
:
1).
E,
antheridia
(150
:
1).
F,
cells with chromatophores and
nucleus (150
: 1).
Fig.
211.
Seirospora occidentalis B0rgs.
A, branch with nearly ripe cysto-
carp.
B, D, young cystocarps (150:1).
C, procarp (150:1).
, FR., Die Gattung Microthamnion
J. Ag. (= Seirospora Harv.)
.
d. deutschen bot.
Gesellsch., Bd. XI,
1893,
p.
273.
224
phores
are thread-like,
shorter
or longer, and irregularly sinuated
(Fig. 210
, E, F).
I have found
plants with tetraspores,
antheridia and cysto-
carps, w
rhich
all
occur on separate
individuals.
The
tetraspores
are
sessile
on
the
uppermost
and
inner
side
of
the
mother-cells
(Fig.
210 B,
C),
when
young
they
are
oval
or
obovate,
when
quite developed nearly spheric-
al;
they
are commonly
tetra-
hedrally divided
more seldom
cruciately
(Fig. 210 C).
The
cystocarps
are
com-
posed of two oppositely-placed
gonimoblasts, which, when ripe,
consist of the
ramified
monili-
form threads of the uniseriated,
nearly
spherical
carpospores
(Figs. 209, 211 A)
;
the
latter
are
about
40
42 ^
broad.
These peculiar seirosporic cysto-
carps
agree
very
well,
apart
from the form
and
size,
with
those
found
in
Seirospora
Griffithsiana Harv. and which
BORNET was
the
-first
(Notes
algologiques,
I
(1876)
p. XIV)
to
explain
as
cystocarps
in
contradistinction
to the
para-
spores
(seirospores)
also occur-
ring in
this
plant.
Fig. 211 C shows a procarp.
I have only succeeded
in find-
Fig. 212.
Seirospora occidentalis Borgs.
Part
of a plant with paraspores.
(About 125:1).
ing remains of the trichogyne, it
seems to be very short-lived as
SCHMITZ
(1. c., p. 280) also men-
tions being the
case
in
Seiro-
spora
interrupta
(Engl.
Bot.).
Most probably
this
is the
reason
why BUFFHAM
!
) has not detected the trichogynes in plants examined
by him.
!
) BUFFHAM, T. H., On the reproductive organs, especially the Antheridia,
of some of the Florideae.
(Journal of the Queckett Microscopical Club,
Vol.
IV,
Ser.
II
(1891)
p.
252).
225
I have
not
been
able
to
see
with
certainty,
in
the
rather
scanty material, whether the carpogonial branch consists
of
3
or
4
cells.
SCHMITZ
(1.
c.)
in
his diagnosis
of
the
genus Seirospora
describes
the
carpogonial
branch
as most often
4-celled, but
in
Seirospora interrupta he found
(1. c. p. 280, note 3) the carpogonial
branch
consisting
of
3
cells
only.
After
fertilization
both
the
auxiliary
cells
begin
to
divide
and
produce
the
ramified,
sporogenqus
filaments
of
which
the
cystocarps
consist.
The
antheridial
stands
are
distributed
in
the same way
as
the tetraspores, placed on the uppermost and inward
side
of the
mother-cell
(Fig. 210 D).
They consist
of
quite
short branchlets
which bear the spermatangia.
Most
often they grow quite
closely
together in dense tufts, sometimes too,
as
Fig. 210 E shows, more
scattered.
When
I described
this plant
I had not come across the para-
spores.
Having now
examined
some more
collections
of
alga?
I
have twice
found plants with
paraspores which
I
refer,
without
hesitation,
to
this
species.
In
one
of the
collections
(from
St.
Thomas,
Fig.
212)
the
specimen
with
paraspores
was
found
together with other fructiferous parts
of this plant;
in the
other
(from
St.
Croix)
the
paraspore-bearing specimen was not found
in company with any other specimen
of
this
species.
The
branchlets
forming
the
paraspores
occur
in
the
same
places
as the tetrasporangia,
viz.
at the upper and inner
side
of
the
cells
in the
filaments.
They consist
of short
cells
filled with
reserve nutriments.
The cells have thick w
T
alls, and become, when
ripe,
nearly
spherical.
The diameter
of
the paraspores
is about
1820 11.
This
species has been found epiphytic upon Gracilaria Blod-
gettii
in a depth
of
about
15 fathoms and besides
I have
found
a few specimens intermingled among Cladophora and Callithamnion
in
about
the
same
depth.
Once
it
was
found
washed
ashore
growing upon an
old
piece
of Sargassum vulgare.
It has been found
in several places
in the sound between St. Thomas
and St. Jan:
e.
g.
off Christiansfort.
St. Thomas
in the sea
to the west
of Water
Island.
St. Croix: near the estate
Lt. Princess (washed ashore).
Geogr. Distrib.:
Hitherto not found in other regions.
15
226
Subfam.
5.
Crouanieae.
\
Antithamnion
Nagl.
1.
Antithamnion antillanum nov.
spec.
Fronde
caespitosa,
fills
repentibus
decumbentibusque,
sub-
strato
adfixis,
fills
erectiusculis ramulis
oppositis
instructis.
Ramuli
alterne pinnati,
pinnis pinnulas singulas
(raro
plures)
in exterior! latere gerentibus
; pinnulis plerumque ex binis-quaternis
(raro
pluribus)
cellulis
compositis,
in
superior!
(interiori)
latere
glandula
ovata
instructis.
Tetrasporangia
cruciatim
divisa,
e
cellula basali pinnularum
orta.
The
base
of
the plant
consists
of
decumbent,
creeping
filaments,
from
which the
erect filaments arise;
often,
too, the ends
of these filaments grow
upwards.
The creeping
filaments are
fastened to
the host plant by
means
of
vigorous
haptera
(Fig. 213).
The
stalk
of
the
hapteron
is
of
variable
length,
often
moniliform,
the
cells
being oval
of shape.
They have thick
walls
; their length varies between 35
65
fj.
or more,
their breadth
is
about
2025/7.
The
stalk
ends
in
a
flat,
disk,
consisting
of coherent
rhizoids.
The
erect
filaments
Fig.
214
are
oppositely
and
distichously
ramified
and bear two kind of branches: some
of them
growing
out
as main
stems
like
themselves,
the
others
as
short
branchlets with
limited growth.
The
cells
in
the
main
stem
are
nearly cylindrical, of variable size from
70200 n
long
and
about
40
50 ^
broad.
Fig. 213. Antithamnion antilla-
Th
branchlets (Fig. 2 15) are alternat-
num nov. spec.
Part of a de-
'
.
cumbent filament from which
mgly ramified, the pinna? being placed
downwards rhizoids, upwards
distichously
along
both
sides
of
the
branchlets are issued.
J
(About 85:1).
rachis.
227
The basal
cells in the branchlets
are
small, nearly quadratic
(comp.
Figs. 213 and
214), while the other
cells
in the
rachis are
nearly
cylindrical,
a
little
thicker
upwards
where
the
pinnae
issue.
The
basal
cell
is very persistent, more
or
less
immersed
in the mother
cell and remains
after the branchlets have died;
as
pointed
out by HowE
1
)
for A. densum
so
in the present
species
also,
rhizoids
grow
out
from
this
cell
;
adventitious,
erect
fila-
ments too
arise from
it.
The
cells
in
the
rachis
of
the branchlets
are from
20
24 ^
broad
and
50
150^
long
or
more.
The
pinnaa
are
simple
or
ramified
and
generally
provided
with
a
single
pinnule
growing
out
mostly
from
the
secund
cell
from
the
base
on
the
distal
side
of
the
pinnae
(Fig.
215).
These
pinnules
(Fig. 216 6,
c, d)
consist
generally
of
two to four, seldom more, cells about
IVa
times
as
long
as
broad
(long,
cell.
=
= 10 f*, lat. 13^).
Nearly every-
one
of
these
small
pinnules
carry
a
large,
oval,
clear
gland-cell
on
their upper
(inner)
side.
This
is 20^
long and
13 // broad.
As
to
the
development
and
position
of
the
glands
the
present
plant seems to come near to A. cm-
datum
according
to
the
description
by NESTLER
2
),
still a few small differ-
ences
OCCUr.
While
in
the
latter
Fig. 214.
Antithamnion antilla-
plant the gland-cell
is in contact with
num nov
: fP
ec -
P?rt
f a Plant -
(About 80
: 1).
3
4 cells,
in my plant,
as
a rule,
it
abuts
on
to
two
cells,
or
more
seldom
three
cells
(Fig. 216
b,
c, d).
Nor have
I ever
in my plant seen the
"stab-oder leisten-
formigen Bildungen" which NESTLER found
in A. cruciatum;
but,
of course,
it must be remembered that
I have not been able to
examine
living
material.
As
to
the development
of the gland-
cells
I have once come across
(in the very scarce material at hand)
1
) HOWE, M. A., The marine Algae of Peru.
(Memoirs
of the Torrey Bot.
Club,
vol. XV,
1914,
p.
151).
2
) NESTLER, A., Die Blasenzellen von Antithamnion Plumula
(Ellis) Thur.
und
Antithamnion
cruciatum
(Ag.)
Nag.
(Wissensch.
Meeresunter-
suchungen,
III.
Bd.,
1,
1899).
15*
228
a young
state (Fig. 216 e)
; this seems exactly
to correspond to the
description and
figures
of NESTLER. A young cell,
the first beginning
to
the
pinnule
carrying
the
gland-cell,
we
find
divided,
by
a
longitudinal,
somewhat
curved
wall,
into
two
cells;
of
these
the
smaller
one
is
the
young
gland-cell,
while
the
larger
cell
afterwards
by
transverse
walls
is
divided
in
two
to
four,
seldom
more
cells.
In the dried material a few tetrasporangia
occurred
(Fig.
216 a).
These
were
of
an
oblong-cylindrical
shape,
about
90 p
long,
and 40 p. broad, with broadly rounded apex
and base
; they were cruciately divided.
The
few
tetrasporangia
"in
situ"
I
have
come
across
were
placed
upon
the
basal
cells
of
the
pinnse
in
the
corner
between
this
and
the
rachis
of the branch.
As
to
the
gland-cells
the
present
Anti-
Fig.215.Antithamnion
thamnion, as mentioned above, is closely related
antillanum nov.
spec.
Branchlet with gland-
cells.
(About 180
: 1).
to A.
cruciatum,
but on
the
other hand
it
differs essentially from this species. As to these
organs my plant seems to come near, also,
to
GRUNOW'S
Sporacan-
thus compactus
1
), but
otherwise
it
has
no
likeness to this plant.
We may point out
as
the
most
charac-
teristic features of our
plant
:
the
alternate
branching
of
the
branchlets
through-
out, the mostly single
pinnule on the under
(outer)
side
of
the
Fig.
216.
Antithamnium
antillanum
nov.
spec.
a, part of filament with
tetrasporangia.
b,
c,
d,
pinnae with gland-cells,
e, development of gland-
cell.
(About 300
:
1).
branchlets
provided
on its upper side with
the
gland-cell,
and
GRUNOW, A., Algse in "Reise der osterr. Fregatte Novara",
1870, p. 60,
tab.
6,
fig.
3.
229
the
large,
subcylindrical tetrasporangia placed,
as
far
as
I have
seen,
at the base
of the
filament.
The plant has been found
as an epiphyte upon old remains
of larger
algae
in shallow water and
in
a rather
sheltered
place.
St. Thomas:
In the harbour of
this island near the town Charlotte
Amalie.
2.
Autithamnion spec.
Having had only a few
sterile,
small specimens
of
this
plant
at my disposal
I
prefer to
let
it remain without a specific name.
The plant has
decumbent,
creep-
ing filaments (Fig.
217),
fastened
to
the
substratum
(Sargassum vulgare)
by means
of
hap-
tera;
these have a
short stalk consist-
ing of more or less
moniliform
cells,
ending
in a
small
irregularly lobed
disk.
The
cells in
the stalk are about
50^ long and
27
ij.
broad.
The cells in the
creeping
filaments
Fig. 217.
Autithamnion spec.
Part
of a decumbent
filament with rhizoids and
erect filaments
(About 175:1).
are nearly cylindrical with thick walls
; they are about
40 p broad
and
115 p.
long.
From these basal
filaments the erect ones
arise;
the ends of these creeping filaments
often being assurgent
too.
The erect filaments are oppositely ramified, each joint bearing
two
branchlets
cruciately
alternating
with
the
pair
below
(Fig.
218).
A few
of
these
branchlets grow
out
as
filaments
like the
main stem
; by
far
the
greater
part
remain
short with
definite
growth.
The
cells
in
the main stem
are
of
variable
size
in the
different
filaments;
they
are
nearly
cylindrical,
a
little
thicker
above the place where
the branchlets
issue; their length varying
about 100 //,
their breadth about 30^.
The
branchlets
are
alternatingly
ramified.
The lowest
cells
in the branchlets
are short
often nearly spherical; the other
cells
230
are
cylindrical
2
3 times
as
long
as
broad.
In
the basal part
of the branchlets the
cells
are about
IQ/j. broad, tapering gradu-
ally upwards; the uppermost ones
in
the end of the filaments are
often
short,
conical.
The
chro-
matophores
consist of irregularly
shaped discs or short
plates.
At the summit
of the young
branchlets
long,
thin
hairs
are
generally present (Fig. 218); these
hairs
are
about
3 p
thick
and
about 80
(JL
long.
Gland-cells
did
not occur
in
this plant.
As mentioned above the plant
was
quite
sterile,
neither
tetra-
sporangia, nor other reproductive
organs were found.
This plant seems to come near
Fig. 218.
Antithamnion
spec.
Part
of an erect filament. (About 140
: 1).
to
A.
cruciatum,
but
the
few
specimens
I have seen were desti-
tute
of
gland-cells,
had
always
opposite,
not
verticillate
branchlets,
these being
alternately, not
oppositely branched.
The
plant was
found
epiphytic
upon
an
old
specimen
of
Sargassum vulgare washed
ashore.
St. Croix:
Near
the
estate
Lt.
Princess
in
the
neighbourhood
of
Christiansted.
Crouania
J. Ag.
1.
Crouania attenuata (Bonnem.)
J.
Ag.
AGARDH,
J., Alga? mediter., 1842, p. 83; Spec. Alg. vol.
II,
p. 105; Epi-
crisis,
p.
84.
HARVEY, W.
H.,
Nereis Bor.-Am.,
p.
226,
pi.
31 D;
Phycol.
Brit.,
pi. 106.
CROUAN in Ann. Sc. Nat., Bot.,
Ser. Ill,
1848,
p. 375,
tab. 12,
figs. 2425.
Crouania bispora Crouan in Ann. Sc, Nat., Bot., Ser. III.
p. 374, tab. 12,
figs. 2123.
Mesogloia attenuata Ag., Systema,
p.
51.
(For more synonyms comp.
also DE TONI, Sylloge Alg.,
vol. IV, Flori-
dese,
p.
1417).
This
species
occurs
in
shallow
water
both
in
exposed and
sheltered places, and in deep water
;
as the specimens vary rather
much according to the
different growing
places
I
shall
first give
a short description of a plant from an exposed locality and after-
wards compare
it with
a specimen from deep water.
231
The
specimen
from
an
exposed
place which
I am
going to
describe was growing upon Amphiroa jragilissima originating from
a coral
reef at the south coast
of
St.
Croix.
The
specimens
found
here
are
scarcely
1 cm.
high.
Their
colour
is
more
or
less
bluish green,
while
specimens from more
protected
places and
from deep water
have a red brown
colour.
The thallus
consists
of a central
ramified filament composed
of large
cylindrical
cells near the upper end
of which a whirl
of
4
di- or trichotomously ramified branchlets
are
issued
(Fig. 219).
The
basal
part
of
the
fila-
ments
is decumbent and fastened
to
the
host
plant by
means
of
rhizoids.
In the most vigorously
developed
rhizoids
the
stalk
is
moniliform
owing
to
the
oval
shape of the thickwalled cells,
in
the
less vigorous cylindrical
;
the
stalk
ends
in
short,
irregularly
ramified
filaments
often
forming
a small disc.
These rhizoids grow
out
from
the
basal
cell
of
the
branchlets
(Fig. 220).
The
cells
in the
central
fila-
ments
are
cylindrical with thick
walls
;
in vigorous filaments they
reach
a
length
of
about
ISO//
and a breadth of 120 p.
They are
not corticated. The branchlets are
repeatedly
di-
or trichotomously
ramified
; the cells
in the branch-
lets
are
broadest
and
shortest
near the base,
tapering gradually
upwards growing at the same time
longer.
The uppermost
ones,
in any
case
in the lower part of the
thallus, are often long cylin-
drical growing up between the filaments of the
branchlets above,
and because
of
this, covering in most cases the main stem quite
densely
(Fig. 219).
In the
cells
of
the
branchlets we
find
well developed
chro-
matophores.
These
consist of a parietal campanulate plate, down-
wards with large openings or with irregularly shaped prolongations.
In the
cells
of
the
central filaments the chromatophores,
on the
Fig.
219.
Crouania attenuata
(Bonnem.)
J. Ag.
Part of
a main
filament with branchlets.
(About
240:1).
232
other
hand,
are much
less developed;
they
are
here
present
as
quite thin ribbons
with
a great distance between them.
If we now compare these small, but robust
specimens
with
the
ones
occurring
in deep
water, we
shall
find
the habit
of
the plant
much
altered.
The
plant
is
much
larger
often
2
3 cm.
high,
but, on the other hand,
much more
slender
and
weakly
developed.
All
parts
of
the
plants
are
more
or
less
elongated,
the
cells
of
the
central
filaments
being
longer,
but
less
broad
and
having
thinner
walls.
The
same
holds
good
with
regard to the branchlets, these
being, on the
whole,
less developed,
shorter, and not form-
ing
such
a dense cover
round
the
axis
as
they did
in
most
cases
in
the
plants from
exposed
places.
As
to
the
reproductory
organs
I
have
only found
tetraspores and
antheridia.
The
tetrasporangia
issue
from the basal
cell
in
the
branchlets
(Fig.
221)
;
they
are
cruciately
divided.
The antheridia are developed quite
in the
same way
as
described
for Crouania Schousboei Thur. by BORNET
and THURET in Notes algologiques
(p. 185,
pi. 49,
fig.
5).
The peri-
pheric cells of the branchlets are repeatedly dichotomously ramified,
and
the
uppermost
ones
of
the
small
cells,
resulting from these
divisions,
are
the
antheridia.
The
plant
has
been
found
with
tetraspores and antheridia
in the months
of
Jan.
March.
As
mentioned
above
it
occurs
as
Fig.
221. Crouania attenu-
-.11
i
n
j
ata (Bonnem.) J.Ag. Bases
well m shallow water as in deeper
; when
Fig.
220.
Crouania
attenuata
(Bonnem.)
J. Ag.
Rhizoid grow-
ing out from the basal
cell
of
a
branchlet.
(About 120: 1).
of branchlets with
young
tetrasporangia.
(About
400:1).
growing in shallow water it
is often found
in
rather
exposed
places
where
it
is
dashed constantly by the waves
:
in such places
it often occurs as
an epiphyte upon Amphiroa fragilissima.
In
deep water
I have
only collected
it once
at a depth
of about
20 meters
;
it was here
fastened to Caulerpa
crassifolia.
Crouania attenuata seems to be
a common species along the shores of
the
Islands.
233
Geogr. Distrib.
:
Mediterranean Sea, warmer shores
of the Atlantic
Ocean.
Subfam.
6.
Spyridieae.
1.
Spyridia filameutosa (Wulf.) Harv.
HARVEY, W. H.,
in HOOKER,
Brit. Flora,
vol.
II,
1833,
p. 336; Manual
Brit Alg., 1841, p. 101
; Phycologia Britannica, pi. 46; Nereis Bor.-Am., 1853,
part
II,
p.
204.
AGARDH,
J., Spec.
Alg.,
vol.
II,
p.
340;
Epicrisis,
p.
268.
FARLOW, W. G., Mar.
Alg.
of New England,
1881,
p.
140,
pi. X,
fig. 1 and
pi.
XII,
fig.
2.
HAUCK,
F.,
Meeresalgen,
p.
115.
DE TONI,
Sylloge
Alg.,
vol.
IV,
sect.
Ill,
p. 1427
(ubi synomyna
pluria).
Fucus filamentosus Wulfen, Cryptogama aquatica in ROEMER'S Archiv
fiir
die Botanik,
III,
1803,
p.
64.
Spyridia filamenlosa
is a very variable plant as
is
sufficiently
clear
from
the many names
the
different
forms
have
received
in
the
course
of
time.
To
understand
this we
need
only
to
consider
the
many
different
forms
KUTZING
has
figured
in
"Tabulae
phycologicaB
1
',
having put
them down as separate forms (comp.
DE
TONI,
1.
c.).
It
is,
of
course,
always
a
difficult
thing
to
decide,
whether any
of
these
forms
really
ought
to
be considered
as a
proper
species
or
not.
But
to
judge from
the West Indian material the
species
seems
to
be
a
very
plastic
plant,
highly
influenced
by
the
external
conditions.
In
the
West
Indies
I
have
found
it
in
more
sheltered
places
and
in
shallow
water.
It
is
common
in
lagoons
and
bays,
but
the mechanical influence of the waves
may
often
be
strong
even
in
such
places
e.
g.
in
certain
places
in
the
harbour
of
Charlotte
Amalia.
Light
is another
factor having much
influence upon the shape of the plant.
Of
course
this
varies
a
good
deal
according
to
whether
the
plant
is
growing
upon
coral
reef
or
atta-
ched to the roots
of mangroves, thus
Fig.
222.
Spyridia
filamentosa
growing in the shade
of these
trees. &**; ?&%&
And again whether
it grows
in
clear
near Christiansted. (About 16:1).
234
water upon
stones
lying upon
the dazzling
white sand bottom
or
in lagoons
in muddy
water.
Often,
too,
it
is found together with
other
alga?
as
entangled masses
lying
loose
upon the bottom.
From
this
it
is clear that
the
external
conditions
under
which
this
plant
grows
in
the West
Indies
are
very
variable.
The specimens
found
are ramified on
all
sides
(Fig. 222).
They have corticated bran-
ches
and
branchlets.
Some
differences,
as
to the more
or
less
rich
ramification
or
to
the
shape
and
size
of
the
bark-cells,
may
occur, but
it
is
not
here that the
essential
differences
are
to
be
found.
It
is
in
the
case
of
the
size
and
shape
of
the
ramuli
that
we
find
the
chief
differences
(comp.
fig.
223).
These may
be
thick,
or
thin,
Fig. 223.
Spyridia fila-
in some
specimens
they
have a broad base
mentosa (Wulf.
)
Harv.
,
,
,
,,
.,
a, a ramulus with long
and
taP er
evenly
upwards,
in
others
they
cells from the specimen
have
nearly
the
same
breadth
along
their
figured in Fig. 222. b, a
111
.1
T,,
n
.
j
ramulus with short cells
whole length.
The
first mentioned end
in a
from the specimen figu-
long attenuate
spine,
the
last
mentioned
in
red in Fig. 224. (About
i
-
rp,
.
.,
,.
100-1).
a snort
spine.
Ihe
cells
in
the
ramuli
are
either cylindrical,
or
barrel-shaped,
in some
specimens
nearly
as
long
as
broad,
in
others
often more
than
three times as long as broad.
No doubt
these
variations
are
due
to
the
influ-
ence
of
different
external
conditions.
For
instance
specimens
growing
in
more open
places, upon coral
reefs
etc.
in
strong
light
have
vigorous,
but
mostly
short
ramuli
with
short
cells,
while
specimens
from
lagoons
growing
in
the
shade
of
the
mangroves
have
long,
thin
ramuli with
long
cells.
In
some specimens
I have found numerous
long, thin hairs issuing from the cortical
cells;
these
were
growing
in
an
open
Fig. 22*. Spyridia
place with much
light.
(Wulf.) Harv.
Part of speci-
The
figure
(Fig.
222) shows a part
men with
short
robust
ra-
&
muh from Cruz Bay, St. Jan.
of a
specimen
from
a more
protected
(About 16
: l).
235
place
with
rather
long
ramuli,
and
Fig.
224
another
specimen
from an open place with
short, robust ramuli.
FARLOW
points
out
(in "The Marine Algse
of
New
England",
p.
140)
that
:
"The
individuals
which bear the cystocarps
are
distinct
from
those
which bear the antheridia.
and may be recognized by
their more
dense
habit".
The
single
cystocarpic
specimen
I
have
come
across was
very
like
the
one figured
in
(Fig.
222).
Fig.
225 shows
a bilobed
cystocarp
;
in the halfpart
to
the
left
the
arrange-
Fig. 225.
Spyridia filamentosa (Wulf.
) Harv.
A cystocarp.
(About 100
: 1).
ment
of
the
carpospores
is
seen.
Fig.
226
is
the
reproduction
of a transverse
section
of
a young cystocarp.
An-
theridial plants were not found.
Some
of the specimens had tetrasporangia.
These occured at
the base of the ramuli, one to three growing out from each bark -ring.
This species
is very common along the shores of
the
islands.
Geogr. Distrib.
: West Indies, warmer parts of
the
Atlantic
Ocean,
Mediterranean
Sea,
Red
Sea,
Indian Ocean.
2.
Spyridia clavata Kiitz.
KUTZING,
F.,
in Linnaea,
vol. XV,
1841,
p. 744;
Spec.
Alg.
p
667;
TabulaB
phycologicaa,
vol.
XII,
tab.
45,
figs,
c,
d.
J. AGARDH, Species Algarum
vol.
II,
p. 344;
Epicrisis,
p.
271.
This plant (Fig. 227)
is originally described
from
a
specimen
from
St.
Thomas
which
KUTZING received
from Senator BINDER.
The
section
of
a
young
description
below
is
based
upon
specimens
cystocarp.
(About
100
: 1).
collected by me, not only at
St. Thomas, but
also
at
St.
Croix.
The thallus
is
terete.
The ramification is distichous, both the
branchlets and the ramuli issuing seriate from both sides of the frond.
Fig.
226.
Spyridia
filamentosa
(Wulf.)
Harv.
Transverse
236
The most
characteristic feature
of
this
species
is the clavate
shape
of
the
branchlets.
The
upper
part
of
the
branchlets
is
thickened, having
for the most part no ramuli, but sometimes
a
few and
scattered ones may be found.
Even the main filaments
are
sometimes
more
or
less
clavate
in
their
upper
end,
most
probably
in such plants
in which the growth begins
to be
slow,
else the main filaments taper evenly towards
their summit.
The ramuli
are
short and
robust,
about
600 n
long.
They
are upwards curved and keep nearly the same breadth from their
base
to
a
little
above
their
middle,
tapering
then
rather
quickly and ending in an acute
spine composed
of
3
4 super-
posed,
small
cells.
Sometimes
the ramuli,
too.
taper towards
their base, these being thickest
in
the
middle.
The
cells
in
the
ramuli
are
mostly
as long
as broad;
in the middle
of the
ramuli about 60
/j. long and 55^
broad.
At the transverse walls
a whorl of small cortical cells are
present.
The
main
filaments
as well
as the branchlets are corticated.
The
cortex
consists
of
alter-
nating
series
of
cells
:
shorter,
oval ones above the
transverse
walls
of
the
large
central
cell
and
longer,
cylindrical
ones
between
them.
The
first men-
Fig. 227.
Spyridia clavata Kiitz.
Part
..
,
,
o-^nv
j
of a plant.
(About 18
: 1).
tloned are about 25-40 // broad
and
45
70// long, the cylindri-
cal
are about 6070^ long and
often not more than
8
jut
broad.
Upon specimens preserved
in
spirit the
large central cells are
very easily seen;
in the main filaments the
joints
are about
2 x /2
times
as broad
as
long.
The nearly
spherical tetrasporangia are
seriately placed upon
the upper
side
of
the
ramuli
near
their
base:
sometimes
the
tetrasporangia occur
also on the lower sides
of the ramuli. They
are
tetrahedrally
divided,
having
thick
walls,
their
diameter
reaching about 50^.
237
This
plant
has
been
collected
partly
in
a more
sheltered
locality
in shallow water, and partly
in the open sea in a depth
of about
12 meters.
St. Thomas:
In the Harbour at Charlotte Amalia.
St. Croix: Of!
Frederikssted.
Geogr. Distrib.
:
West
Indies, Senegambia.
3.
Spyridia aculeata (Schimp.)
Kiitz.
KUTZING, F., Phycologia generalis, 1843, p. 377
; Spec. Alg., 1849, p. 668;
Tabulse phycologica?,
vol.
XII,
pi.
51,
figs,
a,
b.
AGARDH,
J.,
Spec.
Alg.,
Fig.
228.
Spyridia aculeata var.
typica.
Upper end
of
a branch with ten-
dril, and two summits
of ramuli.
(About 18:1 and 200:1).
238
vol.
II,
pars
II-,
p.
342;
Epicrisis,
p.
271.
HARVEY, W.
H.,
Nereis Bor.-
Am.,
1853, part
II,
p.
205.
Spyridia armata
Kiitz., Tabulse phycologicse,
vol. XII,
pi. 50,
figs, c, d.
Spyridia Berkeleyana
Mont,
in
Exploration
scientifique
de
PAlg4rie,
p.
141,
pi.
15,
fig.
6.
Ceramium aculeatum Schimper in Unio
itin.,
n. 966 (non
vidi).
var.
typica
(Fig. 228).
The thallus
is
terete.
The main filaments and branchlets are
corticated;
the
cortex
consists
of
alternating
rows
of
slender,
cylindrical cells and shorter, oblong ones
; the
cylindrical
cells
are
about
55 n
long
and
13 //
broad,
the
oblong
cells
about
40 p
long and 24^ broad.
The branchlets and ramuli issue from
all sides of the branches,
but a more or
less marked tendency to distichous ramification
is
often
present
in
the
specimens
examined.
At
their
base
the
branches are often somewhat slender than higher up in the branch;
e.
g. the base
of a branch was 160 // broad, while higher up the
same branch had a breadth
of 210 //.
Towards their summits the
branches and branchlets taper evenly.
The ramuli
are broadest
at their base and
taper evenly up-
wards.
They
are
about
1 mm.
long.
The
basal
cells
in
the
ramuli
are about 100 // long and 60^ broad,
in the middle of the
filaments only 37^
broad while
their length
is nearly the same.
At the transverse
walls a whorl
of small cortical cells are present.
The
ramuli
end
in
a mucronate
tip
composed
of
2
cells,
and
besides a few (one to three) uncinate
spines
are very often devel-
oped from the
cortical
cells below.
HARVEY
1.
c.
gives
a
good
description
of
this
species.
As
pointed out by this author, which my specimens confirm, the upper
end
of the filaments
is often incrassated and revolute, forming in
this way
a hook-shaped
tendril by means
of which
the plant
is
able
to
fasten
itself
to
other
algae.
The
upper
parts
of
these
tendrils are often more or
less
destitute
of ramuli.
var.
disticha
n.
v.
A forma typica preecipue difTert fronde plus minus regulariter
plumosa, ramis
alternis
distichis ramulisque
a
margine
egredien-
tibus constructa.
The specimens
I
refer to
this
form
are
especially
distinguis-
hed from the typical
one by
the distichous arrangement
of
the
239
branchlets
and
ramuli.
By
this
and
also by
the
very
regular
alternating
of the branchlets the plant has
often a
fine,
feathery
appearance.
To judge from
J. AGARDH'S description
of Spyridia
complanata
this
plant
seems
to
be
very
like
the
present form,
but, while my plant has a terete
thallus, AGARDH'S plant
is
said
to be compressed.
On account
of
this
I
prefer
to
consider my
plant
as a form
of Sp.
aculeata.
Of this form
I have
had
specimens
from
both shallow and
deep water (about 30 meters). The specimens from shallow water
are very robust and
densely ramified
;
the ramuli
are
short and
thick,
composed
of
nearly
quadratic
cells
which,
in
the
lower
part,
are about
70 /^ long and broad.
Uncinate
spines
are deve-
loped,
not only from
the uppermost
cortical
ring in the ramuli,
but sometimes,
too, from the next
one.
Compared with
these
specimens
the
ones
from
deep
water
are much
more slender
in
all
respects.
The ramuli
are
of more
than double the length,
their
cells
slender and
much
longer,
about
50
60 // broad,
130 p
long.
The
specimens
have
a
beautiful,
fea-
thery
appearance.
f.
inermis
n.
f.
A
var.
disticha
praecipue differt aculeis
uncinatis rarissimis aut
nullis.
Fig.
229.
Spyridia
aculeata
(Schimp.)
Kiitz.
var.
disticha
n.
v.
Part
of
a
plant
and
the
upper end
of
a
ramulus.
(About
18
: 1
and
200
: 1).
This form
is cha-
racterized by
the
ab-
sence
of
the
uncinate
spines upon the ramuli. On account of this fact I was at first inclined
to consider
it
as a new
species,
but
after
a
more
thorough
in-
vestigation, having examined
several parts of
different specimens,
I have
twice come
across
a
ramulus
bearing
a
single
uncinate
spine, and
I therefore prefer to
consider
it as a non-aculeate form
of
the
present
species
to
which
it
otherwise
shows
very
great
likeness.
The
specimens
found
reach
a
height
of
more
than
20 cm.
240
The plant
is densely ramified, and the branch lets,
as well
as the
ramuli,
issue distichously from both
sides
of the branches,
these
by
this getting a beautifully
feather-like appearance.
The thallus
is
terete and,
with the exception
of
the ramuli, densely
cortica-
ted.
In
the
younger
parts
of
the
branches
the
cortical
layer
consists of alternating rows
of
cells
as
described
above
for
the typical form, and
like this
one the ends
of
the
branches
and
branchlets
often
end
in
tendrils.
The ramuli,
too, except for
the
absence,
of
the
uncinate
spines,
seem
quite
to
agree
with
those
of
the
typical
form.
They are bent upwards,
having
a
rather
broad
base,
about 60^, and tapering gradu-
ally
towards
their
summit
which consists of a rather long,
mucronate
tip.
At
the
base
the
cells are about
as long
as
broad, higher up about l
1 /^ as
long as broad.
This species has been found
in
shallow
water
in
more
or
less sheltered
localities and
in
deep
water down
to
a
depth
of
about
30
meters.
It
is
mostly
an
epiphyte
fastened
to other
alga?.
F. typica has been found in the
following localities
: St. Croix
: Near
Long Point and at Buck Island in
a depth
of about
5 fathoms.
Var.
disticha.
St. Croix: At the shore near the
estate Cassava Gar-
den.
St. Jan: Off America
Hill
in a depth
of about 16 fathoms.
F.
inermis.
St. Croix: Near the shore at Green Cay Estate.
Geogr. Distrib.
:
West
Indies, Southern Atlantic shores
of Europe,
Maroc, Mediterranean Sea, Red Sea.
Fig. 230.
Spyridia aculeata (Schimp.)
Kiitz.
f.
inermis
n.
f.
Part
of
the
thallus and
summits
of
two
ramuli,
the one with
a
hook.
(About
18
: 1
and 200
: 1).
241
Subfam.
7. Ceramieae,
1
)
Centroceras Kutzing.
1.
Centroceras clavulatum (Ag.) Mont.
MONTAGNE,
C., Exploration scientifique de 1'Algerie,
Algues, Tome
I,
1846, p. 140.
J. AGARDH, Spec. Alg., p. 148; Epicrisis, p. 108. HARVEY, Nereis,
Bor.-Am., Part
II,
p. 211,
tab. 33 C.
Centroceras clavulatum Ag. in KUNTH, Synopsis Plantarum, vol. II, 1822,
p.
2.
Of this
species,
which
is
very common
in
the West-Indian
seas,
a
series of specimens has been examined, frequently differing
from
each
other,
but,
so
far
as we can
judge, the variations
in
question
are
only modifications due
to
different
localities.
Most
of the specimens
are
sterile
; tetrasporangia have been found now
and
then, but no cystocarps.
Centroceras clavulatum
is
fixed
to
the substratum by means
of
rhizoids.
These
have
a
shorter
or
longer
pluricellular
stalk,
ending
in an irregularly lobed
disc.
This
species
is
found
in
very
varying
localities,
from
the
most exposed to
quite
sheltered. Thus
it
is common
in the calm
water
of
the
lagoons,
fixed
to
the roots
of
the mangroves. And
on the other hand
it
is found upon the rocky shore
of the north
west
end
of
St.
Croix, where
it
is
constantly
washed
by
the
waves.
It
seems
to
occur
in
shallow water
only.
In
deep water
it
has never been met with.
It
is very common along
the shores
of the islands.
Geogr. Distrib.
: Seems
to occur
in
all warmer seas.
Ceramium Lyngbye.
1. Ceramium fastigiatum (Roth) Harv.
HARVEY, W. H., Remarks on some British Algae
in HOOKER, Journal
of Botany,
vol. V,
1834,
p. 303.
J. AGARDH, Spec. Alg.,
vol.
II,
p. 119.
Conferva fastigiata Roth, Catalecta botanica,
II, 1800,
p. 175.
f. flaccida
H. E. P.
n.
f.
Ceramium fastigiatum was originally described by ROTH, later
on adopted by HARVEY, supported by Mrs. GRIFFITHS, but with
*) Dr. HENNING
E. PETERSEN has most kindly determined my material
of
the
Ceramieae and
the
systematic
notes
are
due
to his thorough
knowledge
of
this group.
16
242
no indications as to the position
of the tetrasporangia;
J. AGARDH
gives a very good and detailed description of
it.
Judging from that
this
species appears to be
like a Ceramium diaphanum,
regularly
dichotomous and with isolated projecting tetrasporangia. However,
when
these
organs
are
not
present,
this
species
is
not
easily
recognizable.
In referring the present specimens to Ceramium fastigiatiim we
have in view the shape and size of the tetrasporangia. As these, how-
ever, do not seem to agree en-
tirely with the typical form de-
scribed
by HARVEY
(Phyco-
logia
Britannica,
pi.
255)
it
seems
preferable
to
con-
sider them
as
representing a
special form:
f. flaccida, so cal-
led because their filaments are
extremely thin and
flabby.
The
tufts
are
4
5 cm
high,
built
up
by
dichoto-
mous threads. The axial cells
are
about
400 n
long,
50 //
broad,
with
zones
30
40^
high
and
50
fj.
broad,
often
only 20 // high. The
zones do
not
increase
in
the margins;
the upper marginal
cells
are
often smaller than the other
cortical
cells.
No
glandular
cells
are
present.
The
sum-
mits of the filaments
are not
very
curved
and
the
zones
are here quite close together. The tetrasporangia are isolated and
prominent.
Sexual
organs
are not
present.
Of the specimens
of
C. fastigiatu?n distributed
in Phycotheca
Bor.-Am., No.
446
the
uppermost one
of those belonging to the
Botanical Museum, Copenhagen, agrees
in some
respects with the
present
form,
especially
as
to
the
shape
and
size
of the
zones.
The other specimen
is a typical Ceramium stnctum.
Ceramium jastigiatum L
flaccida
is
found
in
sheltered
locali-
ties and
in shallow water and grows upon the
roots
of the man-
groves,
to which
it
is
fastened by means
of
mostly
short,
uni-
Fig.
231.
Ceramium
fastigiatum
(Roth)
Harv.
f.
flaccida
H. E.
P.
a, part
of a
young filament;
b, part of an older one;
c,
zone
with
tetrasporangia.
(About
250:1). H. E. P.
del.
243
cellular rhizoids ending with a
small, lobed
disc;
but longer and
pluricellular rhizoids,
too, are
present.
St. Croix:
Christiansted's Lagoon. St. Thomas: Bovoni Lagoon. St.
Jan: Coral Bay.
Geogr. Distrib.
: Warmer parts of the Atlantic Ocean.
2. Ceramium strictum Grev.
et
Harv.
in HARVEY,
Phycologia
Brit.,
pi. 334.
J. AGARDH,
Spec. Alg. vol.
II,
p. 123.
Specimens belonging to this species were
found
in some few collections together with
other
algae.
The
axial
cells reach a length of up to
400 //, the breadth beinguptolOOy. The zones
are 50
60 // high and 70
110 // broad, thus
a little smaller than is usually
the
case.
Plants with
tetra-
spores and
cystocarps were
found.
The
tetraspores
are
arranged
verticillately
and
often
developed
in
the
nearly straight
summits
of
the
filaments.
This
species
has
been
found
occasionally
in
shallow water
in
both
sheltered
and
exposed lo-
calities.
St. Croix:
In the
harbour of Christiansted,
Coak-
ley Bay.
St. Thomas: Store Nordside Bugt.
Geogr.
Distrib.
Warmer
shores
of
the
Atlantic
Ocean; Mediterranean
Sea.
3. Ceramium
transversale
Collins
et Hervey.
COLLINS, F. S. and A. B. HERVEY, The Algae
of Ber-
muda in Proc. of the American Acad. of Arts and Sciences,
vol.
53, No.
1,
p. 145,
pi. V,
figs. 2931.
This
well
defined Ceramium-species
has been
described
in the above mentioned paper,
recently
published.
It
is
especially
characterized by
the
transversely
elongated
lower
cells
of
the
zones.
Specimens with tetraspores were found.
16*
Fig. 232. Ceramium
strictum Grev. et Harv.
Zone
of a filament.
(About 225:1).
H. E. P.
del.
Fig.
233.
Cera-
mium
transver-
sale
Collins
et
Hervey. Part of
a filament.
(About 370:1.)
244
On the shores
of the islands
this plant was found
as an
epi-
phyte upon Laurencia obtusa upon
the fronds
of which
it
creeps.
It was found
in very exposed
places
in the
littoral
region.
St.
Croix: Hams
Bluff,
Northside.
St. Thomas:
Upon
the
reef
connecting this island with the Hurricane
Island. St. Jan: Cruz Bay.
Geogr. Distrib.: Bermuda, Mediterranean Sea.
4. Coramium
nitens
(Ag.)
J. Agardh.
J. AGARDH, Spec.
Alg.,
vol.
II,
p. 130;
Epicrisis,
p.
101.
Ceramium rubrum var.
nitens
C. Agardh, Systema,
p. 136.
Ceramium
nitens
has
been
found
in
shallow
water and
in
the
sea down to a depth
of
about
10 meters and
in quite
shel-
tered spots
as well
as
in more exposed
places.
It
is
often
found
upon
the roots
of
the
mangroves,
upon
which
it forms rather large
tufts, up
to 10 cms.
or higher. These
are fastened to the mangrove roots by means
of rhizoids issuing
from the lower parts
of the filaments.
These
rhizoids
are mostly
found together in small tufts. They
are rather short and
built up
of
a
stalk,
composed
of some
few
fairly thickwalled
cells,
and
a small irregularly lobed
disc.
Specimens with
tetrasporangia only are met with. These
oc-
curred
in the months
of
January to March.
This
species
is
rather common on
the
shores
of
the
islands. At
St.
Croix
it has already been collected by RAVN, 0RSTED and others.
Geogr. Distrib.: West
Indies.
.
2. Rhodoinelacece.
Subfam.
1. Laurencieae.
Laurencia Lamouroux.
The
correct
definition
of
the
species
belonging to
this genus
according
to
the
material
to
hand
has given me much trouble,
and
I am
afraid
that
I have
not
always
arrived
at
a
definite
result.
In order to arrive at an exact definition a comparison with
authentic specimens would be necessary, but at present, during the
war, this
is out
of the question. The examination
of the
original
specimens
and a revision
of
the whole
genus
seems
to
be very
desirable.
245
FALKENBERG, who
also points out the difficulties encountered
in
attempting
a
definition
of
the
species,
in
his
very valuable
work
on
the Rhodomelaceae,
p.
252,
gives some
starting
points
from which to proceed to the
said
definition
of the
species.
As a
chief characteristic
he
places
the
radial type
opposite
to the
flat, bilateral. He
further quotes the more or less vigorous
ramification,
especially
if the
latter
is
alternate, or shows
a more
or
less
marked
tendency to become
opposite
or
verticillate.
As
an
example
of
a
species
with
alternate
branching
he
names
L. papillosa, as one with
verticillate branching L. obtusa.
Further-
more be mentions as a subcharacteristic the more or less vigorous
development
of the
side-branches, these
in some
species
forming
long
filaments
like the main
filament,
in
others
short wart-like
ones.
FALKENBERG
also mentions
(1.
c.,
p.
246) the
different struc-
ture
of
the
antheridial
stands,
as found
in Laurencia obtasa and
pinnatifida., and points out that such
differences are perhaps
to be
found,
too,
in
other
species. Unfortunately the antheridial stands
are
as yet unknown
in most
of the
species.
1.
Laurencia
Poitei (Lamour.) Howe.
HOWE, M.
A., Phycological
studies,
II,
in
Bull.
Torr.
Bot. Club,
vol.
32,
1905,
p.
583.
Fucus Poitei Lamour.,
Dissertations
sur plus, especes de Fucus, Agen
1805,
p. 63,
tab. 31,
figs. 23.
Laurencia gemmifera Harv., Nereis Bor.-Am., part
II,
1852,
p.
73, tab.
18 B.
Laurencia tuberculosa
J. Ag., Spec.
Alg.,
vol.
II,
p.
Ill,
1863,
p.
760.
Laurencia rnexicana
Kiitz., Tab. Phycolog.,
vol. XV,
1865,
p.
25,
tab.
70,
figs,
c, d.
The
specimens
found
seem
to agree very well with
the de-
scriptions
and
figures
of
HARVEY.
It
is a
relatively large
plant,
often reaching a length
of
15 cm
or more. The
thallus
is rather
robust and cartilaginous.
Upon a transverse
section the central
axis
is not very visible,
the
tissue
consisting
in
the
middle
of
larger, towards the
peri-
phery
of
smaller, roundish
cells.
The
peripheric
cells
are rather
small,
in
transverse
section
nearly subquadratic. While most
of
the specimens had a glabrous
surface, some specimens (my collec-
tions
no. 1504) had
the
peripheric
cells provided with
small pa-
pillae
(Fig.
235). They were
present
in
the
young
parts
of
the
thallus,
in
older
parts
they seem
to
disappear.
I
cannot
say
246
whether we here have to do with a
special
form,
having had
so
few specimens
at my
disposal.
As
to
the
ramification,
this
is
very
irregular,
the
branches
being
of very variable
length, some
short
and some
long
in no
definite
order. They are very
flexuous and spreading to
all
sides.
The branches bear short-
er
branchlets
most
of
these
being very short, tubercle-like.
Only specimens with
te-
trasporangia were found; the
tetrasporangia
are
formed
in
the upper end of the tubercle-
like
ramuli.
This species is gathered in
rather open sea and
in
fairly
deep water, from
5
to 15
fa-
thoms.
St. Croix: off Frederikssted,
White Bay and near Buck Island.
St. Thomas:
In
the sea
to
the
West
of Water
Island.
St. Jan:
off Annaberg and near Thatchkey
Island. According
to
J. AGARDH,
1.
c., the plant
has already
been
found at St. Croix (Hb. Hoffman).
Geogr.
Distrib.:
West
Indies.
2. Laurencia papillosa
(Forsk.) Grev.
GREVILLE, R.
K., Algee
Bri-
tannicae, 1830,
p. LII.
J. AGARDH,
Spec. Alg., vol. II, pars III, p. 756;
Epicrisis,
p.
652.
KUTZING, Spec.
Alg.,
p.
855;
Tab.
Phycologicae,
vol. XV, tab. 62.
Fucus papillosus Forsk., Flora TEgypt.-Arab.,
1775,
p. 190.
Fucus thyrsoides Turner, Fuci,
tab. 19.
Chondria papillosa Ag., Spec. Alg.,
p. 344; Systema,
p. 203.
For more synonyms compare
DE-TONI,
Sylloge
Alg.,
vol.
IV,
sectio
III,
p. 789.
When growing
in
exposed
localities
this plant reaches only
Fig.
234.
Laurencia
Poitei
(Lamour.)
Howe. Part
of the
thallus.
(About 2: 1).
247
Fig.
235. Laurencia Poitei
(Lamour.) Howe. Transverse sec-
tion
of
the peripheric
tissue of
the
thallus. (About
150:1).
a few cm in height, in somewhat more
sheltered
places
it grows higher, up
to
10 cm
or even more.
It
is
firmly
fastened
to
the
rocks
by
means
of
a
broad
and
rather thick disc, from which several,
and
often
many,
erect
branches
grow up.
Growing as
it often does
in the
most
exposed
places,
the thallus
is
of a very firm and cartilaginous con-
sistency.
The
tissue
of
the plant
is
also
built quite according to
its habitat. The epidermal cells, when seen from above,
are
small,
roundish and
have
very
thick
walls; upon a transverse
section
they are found to be long and narrow like palissade cells (Fig. 236).
They
are about
25
/j. long
and
8//
broad.
Also
the
cells
in
the
interior
of
the thallus have thick walls. The
central cylinder
is not
easily distinguishable.
CMy
plants
with
tetraspores
were
found.
These
are formed in the summit of the wart-
like
ramuli.
Fig. 236. Laurenciapa-
pillosa (Forsk.
) Grev.
Transverse section of
peripheric
part
of
thallus. (About 2
It
is
a common
plant
along
the more
open
parts
of the coast
of the islands.
Geogr.
Distrib.
: Warmer
parts
of the
At-
lantic
Ocean,
Mediterranean
Sea, Red
Sea,
Sand-
wich
Islands
etc.
3. Laurencia obtusa (Huds.) Lamour.
LAMOUROUX,
J. V.
F., Essai
in Annales du Museum d'Hist.
Nat.,
vol.
20, 1813, p.
130.
J. AGARDH, Spec. Alg., vol.
II, p.
3,
p. 750;
Epicrisis,
p. 653.
HARVEY.
Phycologia
Brit.,
pi. 148.
Fucus obtusus Huds.
Fl. Angl.,
p. 586. TURNER, D., Fuci, vol.
I, tab. 21.
The specimens
I refer to
this
species
are very heterogeneous,
and
it may be
that
several
different
forms
have
been
classified
together.
What
especially characterizes
this
species
is
that
the rami-
fication has more
or less a tendency to be verticillate
;
this being
especially the
case
in the
var. gelatinosa.
Most
of
the specimens
referred to
this
species show upon a
transverse
section of the young thallus a relatively distinct central
cylinder.
In
older
parts
of
the
thallus
it
is more
indistinct
or
248
altogether absent, and
the
tissue
consists then
of roundish
cells,
larger in the middle, smaller outwards.
Some
of
the
specimens were
small,
often
only
a few centi-
meters high. They often grow like low dense
tufts, in which other
smaller algse find protection,
e. g., Polysiphonia jerulacea,
Ceramium
etc.
Other
specimens
(Fig.
237)
are
large, up
to
15 cm
or even more ; they are much
like
specimens
in MAZE &
SCHRAMM'S collection of algae
from
Guadeloupe
and
by
these
referred
to Laurencia
dendroidea.
They
have
a
terete
stem.
The
branches
issue on
all
sides, but with
some tendency to be oppo-
site
or
verticillate. The
ra-
muli
are
nearly cylindrical
or somewhat
clavate.
A transverse section
of
the
older part
of
the
thal-
lus shows a tissue consisting
of roundish cells of different
sizes, without
any trace
of
a central axis.
In the young
parts
of the
thallus, on
the
other
hand,
this
is
more
clearly
visible.
The
tetrasporangia
are
found
in the summit of the
ramuli.
The cystocarps are pla-
ced
either upon the ramuli,
or upon the
branches which
bear
the
ramuli.
They
are
ovate-
pyriform
in shape, about 230 // long and 170 /^ broad. They open
by a
large
orifice measuring about 60^
in
diameter.
var. gelatinosa (Desf.
)
J. Ag.
J. AGARDH, Spec. Alg.,
vol.
II,
p.
Ill,
p. 751;
Epicrisis,
p. 653.
Fig. 237. Laurencia obtusa (Huds.) Lamour.
Part of the thallus (About 3:1).
249
Fucus gelatinosus Desfontaine, Flora Atlan-
tica, Tomus
II, Paris Anno
6,
p. 427.
Laurencia obtusa var. crucifera Kiitz. Tabulae
Phycol., vol. XV, p. 20, tab. 55,
figs, c
d. HAUCK,
Meeresalgen,
p. 206.
The specimens (Figs. 238239) referred
to
this
variety seem
to
agree
very
well
with the
description
of DESFONTAINE, and
furthermore
with
HAUCK'S
variety
cruci-
fera,
to
judge by
his
description
and by
the
figures
of
KUTZING,
quoted
by
him.
Amongst
these
figures my
plants
seem
most
to
resemble
the
plant
which
KUT-
ZING has called L. cyanosperma (Tab. phycol.
vol. XV,
pi.
58). Some
of my plants
also
had a no
less striking
similarity to
a spe-
cimen
in MAZE and SCHRAMM'S
algae from
Guadeloupe
called Laurencia
intricata.
The specimens
found
in exposed
pla-
ces
are
slender
and
of
very
firm
consi-
stency,
while
those
from
more
sheltered
places
are
larger, broader and more
gela-
tinous,
forming
in
this way a
transition
to the typical Laurencia
obtusa.
Upon a transverse section of the young
parts
of the
thallus the
central axis
is in general
easily
distinguishable
(Fig. 240);
in one
speci-
men from a very exposed
place (my collection no.
1491) the central axis was
not
visible,
the
whole
tissue
being
composed,
upon a transverse section,
of roundish cells, largest
in
the
middle,
smaller
outwards
and
all
having
rather
thick
walls.
My
specimens
form
mostly
rather
dense
tufts, reaching a height of about 10 cm or more.
Fig. 238. Laurencia obtusa
(Huds.)Lamour. var. gela-
tinosa (Desf.) J. Ag. Part
of a male plant.
(About 3
: 1).
Fig. 239. Laurencia
obtusa (Huds.) La-
mour.,
var.
gela-
tinosa (Desf.) J. Ag.
Part of tetrasporic
plant. (About 3:1).
The
thallus
is
slender, pyramidally cylindrical
250
Fig.
240.
Laurencia
obtusa
(Huds.)
La-
mour. var. gelatinosa
(Desf.) J. Ag. Trans-
verse section of the
thallus. (About 60:1).
in
shape.
The main
stem bears
on
all
sides
short branches, usually
verticillate. The bran-
ches
ramify again
once
or several times, the
ramuli
in the tetrasporic plants being subcla-
vate
or
nearly
cylindrical
(Fig.
239).
In the
male
plant, on the other hand, the ramuli are
very swollen at their summit (Fig. 238). Female
plants were not found. The antheridial stands
agree
entirely with the description and figures
of
FALKENBERG,
Rhodomelaceen,
p.
247,
pi.
23,
figs. 1315.
FALKENBERG
states
that
he
found
at
Naples
two
forms
of
Laurencia
obtusa growing together in
the
same
locality.
These
two
forms,
in
all
other
points identical, differ from
each other by their colour:
the one
is green, the other
yellowish
red.
COLLINS
found the same in Bermu-
da.
This
is
also
seen
on
the shores
of
the
islands.
This variety is met with
even
in very exposed
pla-
ces, for instance
it
is com-
mon along the rocky shore
of
the
north-west
end
of
St.
Croix.
It
grows
here
often somewhat above the
level of the sea and is con-
stantly
washed
by
the
strong
surf
nearly always
prevailing here.
Laurencia obtusa is rather
common
along
the
shores
of
the islands. Var. gelatinosa has
been
found
at
St.
Croix:
Northside, Coakley Bay, White
Fig.
241.
Laurencia
implicata
J. Ag. Part
of the
thallus. (About 3:1).
251
Bay.
St. Thomas
in
the
Harbour
of
Charlotte
Amalie;
St.
Jan:
Cruz Bay.
Geogr. Distrib.: Warmer
parts
of
the
Atlantic
Ocean,
Mediterra-
nean Sea.
4.
Laurencia implicata
J. Ag.
AGARDH,
J., Spec. Alg., vol.
II, p. Ill, p. 745; Epicrisis, p. 646. HARVEY,
W. H., Nereis Bor.-Am., Part
II,
p.
72,
tab. 18 D.
It
is not without hesitation
that
I have referred a few spe-
cimens gathered
at
St. Groix to this species.
In doing so
I
partly
rely
on
a
specimen
in
MAZE
and
SCHRAMM'S
collection
of
alga)
from
Guadeloupe named Laurencia implicata,
and
partly
on
the
description
of
J.
AGARDH, which seems to me to agree
rather well with my specimens
; on the
other hand these differ somewhat from
HARVEY'S
description and
figure,
1.
c.,
branching
somewhat
more
regularly
on
all
sides.
The
specimens
reach a height
of
about
16 cm, and
have
a
fine
rosy
Fig.
242. Laurencia implicata
rnlnnr
J- &
Transverse
section
of
the
thallus. (About
60:1).
In
a
transverse
section
of
the
young parts
of the thallus (Fig. 242) the central
axis
is generally
rather
clearly
seen,
having
a
small
central
cell
and commonly
five
large
pericentral
cells. The surrounding parenchymatic
tissue
consists
of rather large and thin-walled
cells; the peripheric
cells
are
relatively
large, about isodiametric
in transverse
section.
The ramuli
are nearly cylindrical
or somewhat clavate; they
are generally alternate,
in some
of the specimens with some ten-
dency to be secund. The tetrasporangia
are found
in the summit
of the ramuli.
The
specimens
were
dredged
in
a
depth
of
about
6
fathoms.
This
species
is most probably described from specimens from
St. Croix,
J. AGARDH giving
as
locality for this
species the above
named
island.
St. Croix:
Off Freclerikssted
; near Buck
Island.
Geogr. distrib.: West
Indies.
252
5. Laurencia chondrioides nov. spec.
Frons csespitosa, axibns
teretibus, flexuosis, crassitudine varia-
bili,
plerumque
ca.
350
//
crassis,
irregulariter
quoqueversum
pinnatim
ramosis,
interdum
suboppositis;
ramis
brevioribus
et
longioribus
intermixtis,
intervallo ramorum
variabili.
Kami
mi-
nores
et ramuli
clavati,
basi attenuata,
apice obtuso.
Tetrasporangia
in
superior!
parte ramulorum
apparent;
lat
tetrasp. = 80^.
Fig.
243.
Laurencia
chondrioides
n.
spec. Part of the thallus. (About 6:1).
Fig.
244.
Laurencia
chondrioides
n.
spec. Transverse section of the thal-
lus. (About 100:1).
The plant forms tufts about 6 cm.
high. The
slender thallus
is terete and of variable thickness, often tapering slightly and again
increasing several times
(Fig. 243).
It
is about 350 //
thick.
The ramification
is very irregular. The branches
issue on
all
sides sometimes with
short, sometimes with long intervals
; some-
times they are nearly
opposite. Shorter or longer branches occur
intermingled.
The branches ramify again once or twice. The
smaller bran-
ches and
the ramuli
are narrowed
at
their base,
increasing gra-
dually upwards
to
above
their middle and then tapering slowly
to the obtuse summit.
The
central
axis
is
fairly distinguishable in the younger parts
253
of the thallus (Fig. 244), not in the older, the thallus here consisting
of roundish,
relatively large
and
thin-walled
cells
in the middle,
smaller ones towards the periphery. Larger and smaller intercellular
openings
are
often
present.
The
peripheric
cells
are, when seen
from above, irregularly polygonal, about 40
//. broad
in the young
parts
of
the
thallus,
in
the
older subcylindrical or barrelshaped,
about 140 n
long
and
35 p
broad
(Fig. 245). Upon a transverse
section they are nearly subquadratic.
The tetrasporangia
are
formed
in the summit
of the ramuli
(Fig.
246);
in
the
specimens
found,
however,
not
in any great
number; they
are about 80 //
in diameter.
Fig. 245. Laurencia chondrioides
n. spec.
Surface
cells of young (to the right) and
older
(to the
left) parts
of
the
thallus.
(About 35:1).
Fig.
246.
Laurencia
chondrioides
n. spec. Part of tetrasporic thallus.
(About
6:1).
.
The
specific name
alludes
to
the
appearance
of
the
dried
specimens, the beautiful rosy colour and
whole
habit
of
which
forcibly
recalls
some
forms
of
Chondria
dasyphylla. When
com-
pared
in more
detail
several
striking
differences
are
noticeable,
for instance
in Chondria
the
large
central
cells
are
clearly seen
through the
cortical
layer, while
this is not the case in Laurencia.
Moreover, transverse
sections show the same
difference.
This plant has
been
dredged only
in
relatively deep
water,
in a depth
of about 30 meter.
Only found once:
St. Jan:
off America
Hill.
6.
Laurencia cervicornis Harv.
HARVEY, W.
H., Nereis Bor. Am.,
II,
p.
73,
tab.
18 C.
COLLINS, FR. S., The Algae
of Bermuda.
(Proceed,
of
the Amer. Aca-
demy,
vol. LI 1 1, No.
1, 1917,
p. 118.)
254
Of
this
species
I
have
only found
a
few
specimens. They
were
dredged
in
rather
deep
water
and
were upon
the
whole
rather
poorly
developed. When
in
good
condition
this
plant
is
very characteristic, and
easily known.
Its
chief peculiarities con-
sist in the very irregular subdichotomous branching, poorer
in the
basal part,
richer in the upper one, the branches on
this account
being very closely placed
at
the
top, and
the whole
thallus
re-
ceiving a roundish
outline. The thallus
is
terete
or nearly
so, and
of about the same
size throughout the whole
plant.
A transverse
section
of
the
thallus
shows
that
the central
axis
is
not very
visible,
the
tissue
consisting
of
roundish thin-
walled
cells. The
epidermal
cell-layer
is composed
of very small
and nearly subquadratic
cells.
My specimens were
sterile. Only dredged once
in a depth
of
about 15 fathoms.
St. Jan: Off Eremitage.
Geogr. Distrib.: West
Indies,
Florida.
Subfam.
2. Chondrieae.
Chondria Ag., Harv.
Subgenus
I. Euchondria Falkenberg.
1.
Chondria polyrhiza
Collins and
Hervey.
COLLINS, F. S. and A. B. HERVEY,
The Alga?
of Bermuda,
p.
121,
pi.
II,
fig. 12. Phycotheca Bor.-Am., No. 2040.
Of
this
species
I
have
found
a
single
specimen
only,
and
unfortunately
it was
dried. But
it seems
to agree quite well with
the description
of COLLINS and HERVEY.
The
plant
apparently
forms a rather
loose
tuft,
5 to
6 cm
high.
The
ramification
is very irregular,
the branches
spreading
out on
all
sides, varying greatly in length. There seems to be no
main
stem.
The
distance
between
the
branches
and
ramuli
is
very variable.
The branches and ramuli
are narrowed
at their base,
taper-
ing upwards evenly into an acute apex.
Here some small tricho-
blasts
are found surrounding the conical, protruding growth-point.
The
peculiar
bunched
rhizoids
are
numerous
and
break
out
everywhere upon the thallus (Fig. 247). As pointed out by COLLINS,
255
they are very like those found
in the genus Herpochondria; com-
pare FALKENBERG, Rhodomelaceen,
p. 218.
The filaments
are about 300
400 /* thick. How far the thallus
is
terete
in my plant
I have
not
been
able to
state,
as
all my
endeavours to make it reassume
its original
form
have
been
fruitless.
The
thallus
in
COLLIN'S
plant
is
cylindrical.
Compared
with the specimen in Phycotheca, my plant
is somewhat
larger and seems to be more
loosely
built,
more
flabby
and
on
the
whole
of a
less
firm
consistency;
the
co-
lour,
too,
is
lighter, more rosy
red.
My specimen
is
sterile.
The plant was dredged in rather deep
water, about
15 fathoms.
Fig.
247.
Chondria poly-
rhiza
Collins
et
Hervey.
Part of the
thallus with
a bundle
of rhizoids.
(About 90:1).
St. Jan.:
Off Cruz Bay.
Geogr. Distr.
: Bermudas.
2. Chondria atropurpurea Harv.
HARVEY, W. H., Nereis Boreali-Americana, Part
II, 1852, p. 22, pi. 18 E.
Chondriopsis atropurpurea
J. Ag., Spec.
Alg.,
vol.
II,
p. 801;
Analecta
Algol., 1892, p. 150. FARLOW, The marine Alga? of New England, Washington
1881, p. 167.
Of this
species
I have found
a
single specimen
only.
This plant
is
especially characterized
by
its dark brown-red
colour and by its inordinate
ramification. The secondary branches
are
constricted at
their base
and
tapering
upwards. The ramuli
have nearly the same shape:
fusiform.
The specimen found
is a male
plant. The
antheridial stands
are placed
as usual at the upper end
of the ramuli.
It was gathered
in
the month
of January
in shallow water
in
a sheltered
locality.
St. Croix: Casavagarden.
Geogr. Distrib.: West
Indies, Atlantic
shore
of the United States,
Brazil? Japan?
3.
Chondria
littoralis Harv.
HARVEY, W.
H.,
Nereis
Bor.-Am.,
Part.
II,
p.
22. FALKENBERG,
P.,
Rhodomelaceen,
p. 197.
Chondriopsis
littoralis
J. Ag., Spec. Alg.,
vol.
II, pars III,
p. 800; Ana-
lecta algologica,
p. 150.
256
The plant
forms dense
tufts
14 cm high or more. The main
filaments
are
about
l
lk mm thick, tapering
gradually
upwards.
They are divided many times and very irregularly, with long and
short
intervals
between
the
forking,
and
often
three
branches
Fig. 248. Chondria
littoralis Harv.
a, Part of a male
plant.
b, Part
of a female plant. (About
6:1).
issue
from
the
same
spot. The
main
filaments
are
bare
in the
basal
part,
higher up
they
bear
scattered
branches
of variable
length; these and the uppermost ends of the filaments are covered
with
ramuli
spreading on ah
1
sides.
As these decrease evenly
in
length
upwards,
all
the
uppermost
parts
of
the thallus assume
a conical appearance
(Fig. 248).
257
Fig. 249. Chondria litto-
ralis Harv.
Transverse
section
of
a
filament.
(About 50:1).
The
ramuli
are
clavate-lanceolate
of
shape;
they
increase
gradually
from
the
very
narrow
base
until
somewhat
above
their middle, from where they taper slowly
towards
the acute
summit.
This
is mostly
densely covered with trichoblasts.
The
thallus
is terete. The central cylin-
der
is
clearly seen upon a transverse section
(Fig. 249), and is surrounded by roundish cells.
The peripheric cells are rather small, subqua-
dratic. The growing point protrudes conically
and
is
densely surrounded by trichoblasts.
The tetrasporangia
are
formed mostly in the summit
of the
ramuli,
sometimes through
almost
their whole length
(Fig. 250);
often, too, in the upper end of the branch which bears the ramuli.
The
antheridial stands (Fig. 248 a) are likewise formed
in the
upper ends
of the ramuli. The diameter of the antheridial stands
is
about 450 //
long.
The
large cystocarps
are placed upon the sides
of the ramuli
(Fig. 248 b)
;
sometimes,
too, they may
occur upon
the
branch
which
bears
the
ramuli. The cysto-
carps have a short
stalk; they are urn-
shaped,
having
a
broad, ovate base,
and after narrowing
upwards,
a
broad
opening. They are
about 1,5mm long
and 800 /*
broad.
The colour
of
the plant is a brow-
nish yellow with a
reddish
tinge.
Compared with
the
description
of
HARVEY,
1.
c. my
plant
shows some
minor
differences.
Thus
the
cysto-
17
Fig. 250. Chondria
littoralis Harv.
a, part of a tetra-
sporic plant,
b, a ramulus with tetrasporangia more
magnified,
(a, about 6:1,
b, about 15:1).
258
carps in
HARVEY'S plant are described
as
"ovate, sessile",
in my
plant they were urnshaped,
short-stalked.
Besides, my plant does
not seem to reach the dimension mentioned by HARVEY. On the
other hand, with regard to the whole habit
of the
plant, the
ra-
mification,
colour,
etc., both seem very
alike, and my plant, too,
stains the paper brownish yellow, as HARVEY points out with
re-
gard to
his specimens.
The
plant
has
been
found
in
shallow water
and
in
rather
protected
places.
It had tctraspores. antheridia and cystocarps
in
the months
of January
March.
It has been found at St. Croix: Lime Tree Bay. St. Jan
: Reef Bay.
Geogr. Distrib.
: West
Indies.
Subgenus
2. Coelochondria Falkenb.
4. Chondria dasyphylla (Woodw.) Ag.
AGARDH,
C..
Spec.
Alg., p. 350; Systema, p
205. HARVEY, W. H., Ne-
reis Bor.-Am.
II,
p.
20. FALKENBERG,
P.,
Rhodomelaceen,
p.
197,
pi.
22,
figs.
418.
Fucus dasyphyllus Woodw.
in
Trans-
act. Linnean
Soc.,
vol.
II,
1794,
p. 239,
pi.
23,
figs. 13.
English
Botany,
tab.
847.
TURNER, D., Fuci,
tab. 22.
Chondriopsis dasyphylla
J.
Ag., Spec.
Alg.,
II, p. 809; Analecta Algologica,
1892,
p. 152.
Laurencia dasyphylla Grev., Algae Brit,
p. 112, pi
14,
figs. 1317. HARVEY, W. H.,
Phycol.
Brit.,
pi. 152. KUTZING,
FR., Tab.
Phycol.,
vol. XV.,
tab.
43.
Chondria
dasyphylla
belongs
to
the subgenus Coelochondria
in which,
as pointed out by FALKENBERG, the
growing
tip
is
sunk
down
and
the
tissue below
it
is
split, and becomes
very
loose,
with
large
intervals
be-
tween
the
cells.
This
plant
is
fairly common
in
shallow water and
in somewhat shel-
oSLdw.) AgtfSnMS
tered
P'aces '
as
an "P^y*
uP n
plant. (About 6:1).
Cymodocea,
Thalassia
etc.
The
spe-
259
cimens
found
here
are
small,
seldom
more
than
5
cm.
high
(Fig. 251).
Plants
with
tetrasporangia
as
well
as
with
antheridia
and
cystocarps
are found.
The tetrasporangia (Fig. 252) are formed in the ramuli, mostly
in
their
upper
ends,
often, however,
in
3 /4
of their length. The
lowest sporangia are the oldest ones. Often,
too, the summit of the branch from which
the ramuli issue, is sporangiferous. The dia-
meter of the tetrasporangia
is about 170
;j..
The
antheridial
stands
are
placed
in
the
upper
end
of
the
ramuli
(Fig.
252),
later
also upon
the summit
of
the main
filament
itself.
The
cystocarps
are
placed
scattered
upon the ramuli and upon the upper end
of the main axis (Fig. 251). The cystocarps
are ovate
-
- spherical about
1 mm broad
and
700 /^
high.
Some few larger specimens were dred-
ged
in a depth
of about
30 meters
; these
specimens were upon the whole more slen-
derly
built,
and
the
ramuli
had
only
1
3 cystocarps
each.
St. Croix: Behind Long Reef near Christiansted. St. Jan: Off Cruz Bay.
Geogr. Distrib.: Warmer parts of the Atlantic coasts of Europe and
America, Mediterranean Sea.
Acanthophora Lamouroux.
1. Acanthophora
spicifera (Vahl) Bergs.
B0RGESEN,
F., Some new
or
little known
West
Indian
Floridea?,
II
{Bot.
Tidsskr.,
30. Bd.
1910, p. 201).
Fucus
spiciferus
Vahl,
Endeel
kryptogamiske
Planter
fra
St.
Croix
(Skrivter
af
Naturhistorie-Selskabet,
5.
Bd.,
2.
Hefte,
1802). ESPER,
Icones
Fucorum,
7. Heft, Niirnberg 1808.
p. 108,
tab. CLIX.
Fucus acanthophorus Lamx., Dissertation sur quelques especes de Fucus,
Agen, An XIII
(1805)
p. 61,
pi. XXX
et XXXI,
fig.
1.
Acanthophora
Thierii
Lamx.,
Essai
sur
les
genres
de
la
famille
des
Thalassiophytes
non
articulees,
Paris
1813,
p. 44. HARVEY, Nereis
Boreali-
Americana,
Part
II,
p.
7,
pi. XIV.
J. AGARDH, Spec.
Alg.,
vol.
II, part
3,
Lund
1863,
p. 819.
Chondria acanthophora
C.
Ag., Spec.
Alg.,
1821,
p.
363; Systema Alga-
rum,
1824,
p. 209.
17*
Fig.
252. Chondria dasy-
phylla (Woodw.) Ag.
Branchlets
with
tetra-
sporangia and antheridial
stands (About
12:1).
260
Fig. 253. Acanthophora spicifera (Vahl) Borgs.
Part of a plant with antheridial stands.
(About 10:1).
filaments, the branches issuing from
no
spiny
branchlets,
as
is
the
rule
FALKENBERG, Rhodomelaceen,
p. 226).
stop
their
growth,
becoming
short
branchlets. But now and then a single
one
of
these
branches grows out to
filaments with continuous growth, like
the main filaments. The branches and
branchlets are arranged
spirally with
a
l
l
divergency upon
the
filaments.
The
spines
are
found
mostly in the
upper end
of the branchlets.
The branches 'issue from the ba-
sal
cell
of the
trichoblast,
just
as
in
the
case
of
Acanthophora
orientalis,
as pointed out by FALKENBEEG,
1.
c.
p. 231.
In
fig. 255 the summit
of a
plant
is shown
in which a great deal
of the trichoblasts covering the sum-
mit
are
taken
off.
From
the
basal
cells
of
the
trichoblasts
we
see
a
young branch
issuing, the beginning
of
the branchlets
or branches.
It
is
As pointed out in my
paper quoted above, this
species
ought
to
have
VAHL'S
old
name,
being
originally
described
by
him from specimens from
St. Groix. For further de-
tails
as
to
this matter
I
refer to my paper.
Acanthophora spicifera
is
fastened
to
the
sub-
stratum by means of a lar-
ge, irregularly lobed
disc,
from
which
often many
erect filaments
issue.
It
belongs
to
the
group
of
species
which
lack spines upon the main
these
having
at
their base
in
the other group
(comp.
Most
of the branches soon
Fig.
254.
Acanthora
spicifera
(Vahl) Bergs. Part of a plant with
tetrasporangia.
(About
10
: 1).
261
further
seen
from
the
figure
that
the summit
of
the plant
is
protru-
ding in the form of a py-
ramid and not "bisweilen
einer
kleinen
Scheitel-
grube
eingesenkt"
as
mentioned
in
ENGLER
und
PRANTL,
Naturl.
Pflanzenfam.,
I
Teil,
Abt.
2,
p.
435-6. When
in
full growth the sum-
mit of the plant
is quite
enveloped and protected
Fig. 255. Acanthophora spicifera (Vahl) B0rgs.
Summit
of
a
filament showing
the
axillary
branches
issuing from
the
basal
cell
of
the
trichoblasts. The tissue in the middle has been
somewhat spoilt during the preparation.
(About 270:1).
by trichoblasts. As the
figure shows, the plant has a large apical
cell, somewhat
longer than
broad,
from
the
base
of which
flat
segments
are cut
off. Each
of these segments bears a trichoblast,
the basal
cells
of which
are
developed
before
the segments
are
divided.
A transverse
section (Fig. 256) of the stem shows the central
cell and
the
five
pericentral
ones
surrounded by a thick paren-
chymatic
layer
of
cells,
larger and with
thin walls
inside,
small
and thickwalled
at
the periphery.
Plants have been found with tetraspores,
antheridia and
cy-
stocarps.
The tetraspores
are
developed
in
stichidial ramuli provided
with spines
(Figs.
254,
257 C],
in contrast to the
spineless, ovate
roundish
stichidia
of Acanthophora
Delilei Lamx.,
as
mentioned
and
described
by FALKENBERG,
1.
c.,
p. 229,
tab. 22,
fig.
3.
But
it
is
sel-
dom
that
I have
found
stichidia
in
form
like
those
of
Acanthophora
Delilei, in which
case there was only
a
single
bare
one
in
the upper end
of
the
filament, the
other
stichidial
branchlets
all
having
spines (comp.
fig. 257 C}.
The
stichidial
branchlets
of
the
Fig. 256. Acanthophora spicifera
present
species
are
very
similar
to
(V
sec!!onTthI
rSur
thos
of Acanthophora onentalis 3. Ag.
(About
50:1).
as
figured by OKAMURA
in
"Icones
262
of Japanese Algae", vol. I, pi. VIII,
figs. 6
7. The tetrasporangia are
developed generally
in abundance throughout the whole
stichidial
body, in every case
in
the short
ones,
in the longer ones mostly
in
their upper end; sometimes the tetraspores
are
also developed
in
the upper
end
of
the
filaments which
bear
the
tetrasporic
branchlets.
As
I
have
already
remarked, the
antheridial
stands
of
the
genus Acanthophora have only been found
in Acanthophora orien-
talis. ASKENASY has described and
figured them
in "Forschungs-
Fig. 257. Acanthophora spicifera
(Vahl)
Borgs. A, ramulus
with
antheridial
stand. B, a cystocarp.
C,
part of a
tetrasporic plant with stichidial ramuli.
(About 20
: 1).
reise
S. M.
S. Gazelle",
IV Theil,
1888,
Botanik
(Algen),
p.
48,
tab. IX,
figs. 11 and 12.
In my material
of Acanthophora spicifera
male
plants were
fairly abundant and the antheridial stands (Figs.
252, 253 C)
seem
to
be
very
similar
to
those
of
Acanthophora
orientalis.
The
antheridial
stands
of
Acanthophora
remind
one
very much
of
the
well-known
ones
of
the
genus
Chondria,
so
splendidly figured by THURET
et BORNET in Etudes phycologiques,
p. 88,
pi. 45 and
46.
The
antheridial
stands
are
developed
from
the
first
side
branch
of
the trichoblast
(Fig. 258 A),
the
sterile
part
of
it
is
commonly very perishable and
the
fully developed,
ripe
antheri-
dial
stands
are
therefore
placed apparently terminally upon the
263
shorter
or
longer
basal
cell
of
the
trichoblast.
The
antheridial
stand
itself
is
a
flat
disc-formed
body,
generally with a rather
irregularly formed circumference. The margin is composed of large,
oblong,
thick-walled,
clear
cells;
inside
these
both
the
surfaces
are
densely
covered
with
the
spermatia-forming
cells,
through
which
in the middle
of the
antheridial stand we
see a system
of
filaments ramified subdichotomously in the same plane .(Fig. 257.4).
These filaments FALKENBERG
(1.
c.,
p. 201), who has
followed the
development
of
the
antheridial
stands
in
Chondria
dasyphylla,
Fig.
258.
Acanthophora
spicifera
(Vahl)
B0rgs.
A,
trichoblast
with young
antheridial
stand.
B,
older
antheridial
stand.
C, transverse
section of an
antheridial
stand.
D, part
of
the same more
magnified. E, the same seen
from above.
(A, about 200:1; B,
75:1;
C. 160:1; D and E,
400:1).
explains as being the central cells and the cells, which bear the sper-
matia-forming
cells
as being the
pericentral
cells. As shown
in a
transverse
section
of
the
antheridial
stand
(Fig. 258 C},
cavities
are present between the filaments
in the
interior.
The development
of the
antheridial stand seems
entirely
to
agree with
that
of
Chondria
as
described by FALKENBERG,
1.
c.,
p.
201,
pi. 22,
figs. 12
14. The ramification
of the branch which
is destined to
be
the antheridial stand
is made
quite
in accord-
ance with the
sterile part
of the trichoblast, only that its branch-
lets
are
not
free,
but
connected
together.
Fig. 258 A
shows
a
rather young
stage,
and
fig.
258 B
shows
a
fully
developed
antheridial stand.
In
Fig. 258 D we
see a transverse section of the
264
pericentral
cells, and from
fig. 258 E
it
is seen that each of these
cells bears 34 antheridia.
Of cystocarps
I have
only found some
few,
of which one
is
figured
in
fig. 257 B.
This
species
occurs
especially in
shallow water and
in
shel-
tered
places,
but
it may
also
be met
with
in somewhat more
open
localities.
In
sheltered
places,
e. g.
in the lagoons, where
it
is
a common
and
characteristic
species
in
the
communities
of
alga? which
grow upon
the
roots
of the mangroves, the form
of
the plant is more slender, the ramuli are placed at greater intervals
and bear fewer spines, and the colour
of the plant
is often darker.
In the lagoons
and
in
sheltered
places
it often occurs
also lying
loose upon
the
bottom, forming
entangled masses
together with
other
algae.
In
the more
open and exposed
localities
the
plant
is more
robust.
Acanthophora spicifera
has
been
found with
tetraspores.
an-
theridia and cystocarps
in the months
of January
March.
It
is
a very common species on the shores of the islands.
Geogr.
Distrib.-. West
Indies,
Brazil,
Biarritz.
2. Acanthophora muscoides
(L.) Bory.
BORY DE
ST. VINCENT
in
Duperrey, Voyage
autour du Monde, Bota-
nique, Cryptogamie
1828,
p.
156.
J. AGARDH,
Spec.
Alg.,
p.
816.
KUTZING,
FR., Spec. Alg.,
p. 859.
Tabulae Phycol.
vol. XV,
tab. 77. FALKENBERG,
P.,
Rhodomelaceen,
p.
230. OKAMURA,
Icones.
Jap.
Alg.,
vol.
I,
pi.
8,
figs.
810.
Fucus muscoides
L., Spec. Plant.,
1753,
p. 1161;
I763 ;
p. 1630.
Chondria muscoides Ag., Spec.
Alg.,
p. 361.
Acanthophora militaris Lamour. Essai Thalassiophytes in Ann. du Mu-
seum,
vol. 20,
1813,
p. 132.
Acanthophora Delilei Harv., Nereis Bor.-Am.,
II,
p. 18.
The
few specimens
found
are
small,
about
6
7 cm
high.
Like
the
preceding
species,
the
present
one
is
fastened
to
the
substratum by means
of
a
flat
disc,
from
which
several
erect
shoots
grow
upwards.
The
ramification
is
more developed, and
the plants
form
more
dense
bushes
than
those of Acanthophora
spictfera.
Acanthophora
muscoides
belongs
together with
.4.
Delilei
to
the group
of
species,
in which now and
then
isolated
spines
are
found upon the main stem, and the branches
issue from the
cor-
265
ners
of
the
spines
as
adventitious
branches
(FALKENBERG,
1.
c.
p.
227).
Further
the
branchlets
have
mostly
spines
from
their
base upwards.
The
ramuli with
tetrasporangia
are
very
spiny;
the
tetra-
sporangia
are
often
found
too
in
the
summit
of
the branchlet
which bears the ramuli.
The cystocarps
are placed upon
a
thick
spine-like
ramulus;
FALKENBERG who
has
followed
the
development
in
the
case
of
A. Delilei says
it
is a leaf
(1.
c.,
p. 230).
The
cystocarps
are
ovate-urnshaped
bodies,
with
a
large
opening at their summit.
Only gathered once
in
shallow water
in a somewhat
protec-
ted
locality.
St. Thomas: The Hurricane Island in the harbour of Charlotte Amalia.
Geogr. Distrib.: West
Indies, Florida,
Brazil, Cape, Japan
etc.
Subfam.
3. Polysiphonieae.
Polysiphonia Grev.
As
most
of
the
descriptions
of
the Polysiphonias
found
in
the West Indies and surrounding waters are rather
deficient and,
without
access
to
original
specimens, any precise
determination
is
therefore
difficult,
I
fear that some
of my determinations are
not quite
exact.
The following six species have been found
in the area exami-
ned; they can be arranged
in the following way:
A. With axillary branches.
a. With four pericentral
cells.
. Diameter of the
filaments about
90//..
1. Polysiphonia havanensis.
ft. Diameter of the filaments about 35 p..
2. Polysiphonia spec.
b. With 57 pericentral
cells.
3. Polysiphonia variegata.
B. Branches formed without connection with the
trichoblasts.
a. With four pericentral
cells.
a. Diameter of the erect filaments about
100 //.
I. With nearly spherical cystocarps.
4.
Polysiphonia sphserospora.
II. Cystocarp
urceolate.
5. Polysiphonia
macrocarpa.
p. Diameter of the filaments about 200
300 ,u.
6. Polysiphonia ferulacea.
266
1.
Polysiphonia havanensis Mont.
MONTAGNE.
J. F.
C., Cent, plant, cell. exot. nouv. (Ann. sc. nat., Bot.,
II.
Ser.,
t.
8,
1837,
p. 352). RAMON DE LA SAGRA, Hist
nat. Cuba,
p. 34,
tab. 5,
fig. 3. KUTZING, FR., Spec. Alg., p. 818; Tabulae Phycologicse, vol. XIII,
t. 72,
fig. a
d. HARVEY,
Nereis
Bor.-Am.,
II,
p.
34.
J. AGARDH, Spec. Alg.,
vol.
II, pars
III,
p. 959.
The specimens reach a height
of up
to
10 cms.
This
plant
has
four
pericen-
tral
cells,
and no
cortical layer
is
present. The branches are
formed
in connection with the trichoblasts,
not exactly in their axils, but push-
ed somewhat to the side (Fig. 261);
they are mostly formed on the left
side
of the trichoblast
(the katho-
dic
side),
sometimes
too
on
the
right
side.
The base
consists
of creeping
filaments;
these
have
thick
walls
and
are
often rather torulose, the
filaments
being
thickest
at
the
cross-walls;
f.
i.
one
filament was
250
fj.
at
the
cross-walls, but only
170 a
in the middle between them
(Fig. 260).
The segments
in the creeping
filaments
as well
as
in
the whole
plant are of rather variable length,
sometimes shorter than their length,
sometimes
3
4 times longer than
their breadth.
The basal
filaments
are
fixed
to
the
substratum
by
means
of
rhizoids
breaking
out
everywhere
from
the
pericentral
cells,
but
mostly near
their crosswalk
(Fig.
260). The
rhizoids
have no
cross-
walls
; they have rather thick peri-
pheral
walls and end
in
an
irregularly lobed
disc.
The
cylindri-
cal part
is about 25
(JL
thick.
Fig. 259. Polysiphonia Havanensis
Mont. Part of filaments with
tri-
choblasts. (About 16:1).
267
The erect filaments vary much
as to their thickness and the length
of the segments.
Generally the
fil-
aments
are about 90 // broad and
the
length
of
the
cells
is
about
140 fj., but thinner as well as thicker
specimens
occur. This varying de-
velopment
of the filaments
is due
to their
different
ages,
as new ad-
Fig.
261.
Polysiphonia
havanensis
Mont.
a. upper end of a filament with
trichoblast
and
branches;
b,
part
of
a
filament with
trichoblast and branch placed at the katho-
dic side
of
the
trichoblast.
(a, about 270:1,
b, about 360:1).
Fig.
260.
Polysiphonia hava-
nensis Mont. Part of a filament
with rhizoids and adventitious
branch. (About 50:1).
ventitious
branches
are
formed
continually
(Fig.
260).
So
far
as
I
have
seen,
these
young
fila-
ments always seem to be
connected with the basal
cell
of the former tricho-
blast,
or
with
remains
of
it.
The
trichoblasts
are
mostly well developed, a
single one emerging with
a
1
/i divergency from each
segment
(Fig.
259). They
generally
cover
quite
densely
the
top
of
the
filaments,
and
are found
rather
far
down
upon
them.
Most
of
the
speci-
mens
are
quite
sterile;
a
few
specimens
only
with
tetrasporangia
are
268
found.
The
tetrasporangia
occur
in
the
upper part
of
the
fila-
ments
and
are
rather
scattered,
being
either
solitary or a
few
together, with
sterile
segments
between.
The
tetrasporangia
are
about 70
IJL broad.
As
I
have
previously
pointed
out
1
),
this
species
is
found
upon
the roots
of
the mangroves
in
the lagoons; but
it occurs
also
in the
sea
in deep water, about
8 fathoms or more.
It has already been found
at
St. Croix by 0RSTED.
It seems
to be not altogether common on the islands.
St. Croix:
Christiansted's
Lagoon,
Salt River.
St. Thomas: Bovini
Lagoon. St. Jan:
Off America
Hill.
Geogr. Distrib.: West
Indies. Key West.
2.
Polysiphonia
spec.
Some
small
tufts
of a quite
sterile Polysiphonia were
found
creeping upon
old
timber.
It
has
four
pericentral
cells and
its
branches
are developed
at the base
of the
trichoblasts.
The basal
part
(Fig.
262)
of
the
tufts
is formed by decum-
bent, creeping filaments, composed
of rather short
cells, the
seg-
ments being nearly
as long as
broad, about
50//.
Often
rhizoids
are
developed,
from
every
segment, forming
in this way a long
series
(Fig. 262). The
rhizoids
have no
cross
walls and end
in a small
disc
fixed to the substratum.
From these basal filaments the erect ones
arise. At their base
these
arc
of nearly the same
size
as the basal
ones, towards the
upper
part
they
taper
gradually to
about
one
half
of
their
diameter.
The cells have nearly the
same length, being about
one
to
one
and a
half
times the breadth of the
filaments.
In the upper
part of the filaments each
of
the segments
carries
a
trichoblast
placed
in
a
spiral
line
with
a
x
/
divergency
(Fig.
263).
Fig. 262. Polysiphonia spec.
Base of a iilament. (About 80:1).
*) B0RGESEN, F. The
algal vegetation
of the lagoons in the Danish West
Indies (Biologiske Arbejder tilegnede EUG. WARMING, K0benhavn 1911,
p.
48).
269
The branches
are
placed
in the
axil
of
the
trichoblast,
or
more
correctly they are pushed a
little to
the
left
side
of them
(Fig. 263).
By its way of growing and whole
construction and habit
this plant
re-
minds one very much
of
the prece-
ding
species, but
being quite
sterile
it
is impossible to give a more exact
definition
of
it.
Found once
in shallow water near the
shore in Store Nordsidebugt (Magens. Bay) ;
St. Thomas.
3. Polysiphonia variegata (Ag.) Zan.
ZANARDINI,
G.,
Synopsis
alg.
mar.
Adriat.
in
Memorie
Real.
Accad.
d.
To-
rino,
Serie
II,
T.
IV,
1842,
p.
162.
J.
AGARDH,
Spec.
Alg.,
vol.
II,
3,
p.
1030;
KUTZING, Spec. Alg., p. 821; Tab. Phycolog.,
XIII,
tab.
81.
HARVEY,
Phycolog.
Brit.,
pi.
155;
Nereis
Bor.-Am.,
part
II.
p.
45.
THURET
ET
BORNET,
fCtudes
Phycolo-
giques,
p.
86,
pi.
42.
FALKENBERG, Rho-
domelaceen,
p.
119,
tab.
21,
fig.
30.
BER-
THOLD,
Beitr.
z. Morphologic und
Physio-
logie der Meeresalgen
(Pringsh. Jahrb.
13,
Fig. 264* Polysiphonia variegata
(Ag.) Zan
Basal part
of a filament with rhizoids.
(About 260:1).
Fig. 263. Polysiphonia spec.
Part
of filament near its sum-
mit with trichoblasts and
branches. (About 350
: 1).
pi. XX.
fig. 816)-
Hutchinsia variegata Ag.
Systema, p
153.
Cfr.
DE-TON i,
Sylloge
Alg. Vol.
IV.
Sect.
Ill,
p.
922, ubi syn.
pluria.
The plant grows upon
the
roots
of
the man-
srroves and forms dense
o
bushes up
to
10 cm
or
more
in
height.
It
is
fastened to the substra-
tum by means of nume-
rous
rhizoids
issuing
from
the
decumbent
creeping
filaments
(Fig.
264).
The
rhizoids
are
270
as
a
rule not ramified and end
in a small
irregularly lobed
disc.
The
rhizoids are separated by a cross wall from the mother
peri-
central
cell. The
cylindrical part
of the
rhizoids
is 50 //
thick.
Fig. 265. Polysiphonia variegata (Ag.)
Zan. Summit of filament with tricho-
blasts and branches.
(About 200
: 1).
Fig. 266. Polysiphonia variegata (Ag.
Zan.
Part
of
filament
with
tetra-
sporangia. (About 30:1).
The plant has commonly 6 pericentral cells, sometimes
in the
basal part
7 and
in the upper part 5 only. No
cortical layer was
found in my specimens.
The branches
(Fig. 265)
are found
in the axils
of the tricho-
blasts pushed to the left side of them as drawn by FALKENBERG
in
ENGLER und
PRANTL,
Nat.
Pflanzenfam,
I
Teil, Abt.
2,
p.
439,
271
fig. 246 E. The distance between the branches
is great; as pointed
out by FALKENBERG these
are most
often found upon every
fifth
to eighth
joint.
The tetrasporangia
(Fig. 266) are found
in the upper part
of
the
branches
in
shorter
or
longer
rows.
The tetrasporangia are
proportionately
small, and
the
branches
in
which they are
im-
bedded
are not much
swollen. The cystocarps
are broadly ovate
or nearly spherical and have
short
stalks.
The antheridia
I have not found
; these are beautifully figured
by THURET
in
Recherches
sur
les
anthericlies
des cryptogames
(Ann.
sc.
nat.,
Bot.,
3.
ser.,
vol. 10,
pi. 6) and
in Etudes Phyco-
logiques,
1.
c.,
This
species
is a characteristic lagoon-plant living in the often
very
dirty
water
found
here. Together with other
alga?
it often
forms a dense coating upon the roots
of the mangroves, and
like
these
its
tufts are more
or less covered with mud.
In clear water
it does not seem to
occur. HARVEY, in Phycologia Britannica, pi.
155, has
already mentioned
this
peculiarity,
as to
its occurrence
and
this has
later on been pointed
out by FALKENBERG, Rhodo-
melaceen,
p. 119.
Plants with
tetrasporangia
and
cystocarps have been found
in January.
St. Thomas: Bovoni Lagoon. St. Croix: The Lagoon of Christiansted,
Salt River Lagoon.
Geogr.
Distrib.: The
Atlantic
coast
of
North
America,
the
West
coast of Europe, Mediterranean Sea.
4.
Polysiphonia sphserocarpa nov.
spec.
Frons
dense
caespitosa,
csespitibus
parvis,
circiter
1
! 1
/ 2
cm
altis.
Fila non corticata siphonibus
pericentralibus
quatuor.
E
filis repentibus decumbentibusque, rhizoideis substrato
ad-
fixis,
fila
erecta
gignuntur.
Fila
in
parte
basali
circiter 100
/./
crassa:
cellulis
ca.
150 p.
longis.
Ramificatio
subdichotoma;
ramis
erectis extra
axillis tricho-
blastorum
ortis,
angulis
acutis.
Tetrasporangia in superiori parte filorum, sa?pe furcata, posita,
seriata.
Lat. tetrasporangiorum
= = 60//.
Cystocarpia
fere
sphaBrica,
ca. 80 p longa
et
lata.
272
The plant
forms
small low
tufts
about
1
1
]
/ 2 cm high;
it
was
found
near
the surface
of
the
sea, where
is was constantly
washed by the waves.
It has four pericentral
cells
(Fig. 2676).
The base consists
of
creeping decumbent
filaments fastened
to the substratum by means
of
rhizoids
breaking
out
from the
lowermost
cells
in the
fila-
ment, sometimes two
from
the same
cell
(Fig. 267 a).
The thicker
basal
cells
are about 150^,
sometimes
up to
200 ft
thick
and
the
length
of
the
cells
about
125^;
but
these
filaments
are often much thinner, some-
times
not
more than
60
/;.,
and the length
of
the
cells
about
100
.
The
creeping
filaments
bend upwards
in
their upper end, forming in
this way an even transition
to the erect filaments (comp.
fig. 267
a).
The
latter,
too,
are often provided with hap-
ters which
fix themselves to
neighbouring filaments,
ser-
ving in this way to keep the
tuft together.
The erect
filaments, whether they issue from the creeping fila-
ments or are the upwardbent summits of these, taper evenly towards
their summit.
In
the basal part they are
about 100^ thick and
the
cells
about
150 /^
long;
near
the
summit
the
filaments
are
mostly only half
as broad
as
at
their base.
In the thinner
fila-
ments the
cells
are sometimes three times as long as the diameter
of
the
filament
;
f .
i.
a
filament was
about
60
jut thick and the
cells about 175 u
long.
While
in the
older parts
of the
thallus the
filaments
are
al-
most
cylindrical, the segments
in the young parts
are
often
sub-
sphaerical
or
barrelshaped,
and
the
filaments
in
this way get a
moniliform appearance
(Fig. 268).
The
branches
issue without any
connection with
the trich-
oblasts
(Fig.
269).
The
latter
are
developed
upon
each
seg-
Fig.
267.
Polysiphonia
sphserospora
nov.
spec,
a, Base of a filament with rhizoids.
b. transverse section
of a filament.
(a, about 50:1,
b,
130:1).
273
ment or sometimes they are substituted by a branch. The tricho-
blasts are shed early and
are mostly present only at the summit of
the
filaments. The plant
is repeatedly pseudodichotomously rami-
fied. The branches are erect, nearly parallel,
issuing at acute
angles.
The tetrasporangia
(Fig.
270) occur
in
the upper ends
of the filaments, which
are
often several times
forked. They are placed
in a spiral line in long series. They are about
60 a
in diameter.
Fig. 268. Polysiphonia
sphserocarpa nov. spec.
Part of a female plant.
(About 30:1).
Fig. 269. Polysiphonia
sphserocarpa nov. spec.
Part of filament with
branch. (About 260:1).
Fig. 270. Polysiphonia sphse-
rocarpa nov. spec. Upper end
of filament with
tetraspor-
angia. (About
60:1).
The cystocarps
(Fig.
271)
are
nearly
spherical,
placed
upon
a short, thick
stalk. They are about
80//. long and
of nearly the
same breadth.
This
plant
seems
to
show much
resemblance
to
P. fem-
lacea
but
it
is
in
all
respects
a
far more
tiny
plant.
It was
18
274
nov.
spec. A nearly
ripe
cysto-
carp. (About
200:1).
found
in
company
with
P.
fern-
lacea.
Only
found
once:
St.
Thomas:
Store Nordsidebugt.
5. Polysiphonia macrocarpa Harv.
HARVEY, W.
H.,
in MACKAY, Flora
Hibernica, part
3,
Algas,
p. 206. BORNET,
E.,
Les
Algues
de
P.
K.
A.
Schousboe,
p. 306,
pi.
Ill,
fig.
5.
Polysiphojiia pulvinata
Harv., Phy-
cologia
Britannica,
pi.
102 B.
KUTZING,
Tabuhe Phycologicae,
vol. 13,
pi. 36 a -e?
This
plant
is common
on
the
roots
of the
mangrove,
and
forms
Fig.211.Polysiphoniasphserocarpa
dense, dark red-brown
tufts, up to
10 cm
or
higher.
The
thallus
has
four
pericentral
cells.
There
is no
cortical
layer.
The
base
(Fig.
272)
of
the
plant
consists
of
decumbent,
creeping, more
or
less
ramified
filaments,
from the
lower
surface
of which rhizoids
issue,
fastening
the filaments to
the substratum. The rhizoids grow out from the
pericentral
cells
and are
in
permanent
open
connection
with
the mother-cell, having
no walls, either at their
point
of
origin or else-
where.
They
have
a
longer or shorter cylin-
drical
stem with very
thick
peripheral
walls,
leaving
only
a
very
narrow
channel
open
in the middle, and end
in
irregular
lobes,
of-
ten
forming
a
small
disc.
The
rhizoids
are
of
variable
length,
shorter
or
longer
in
proportion
to
the
di-
*}& ^
2 -
Polysiphonia
macrocarpa
Harv.
Base
of a filament with rhizoids and erect branches,
tance
irom
the
sub-
(About
20:1).
275
stratum, mostly about 800 p.
long; the cylindrical part
is
about 40
IJL
thick.
The
creeping
filaments
have
thick walls
and
sinu-
ated periphery, the filaments
being thickest
at the cross-
walls;
the
filaments
are
about 100
150 // or thicker.
The
length
of
the
pericen-
tral
cells
in
these filaments
varies about 150 //.
From
these
creeping
filaments
the
erect
ones
grow
up.
The
peripheral
walls
in these are
still thick
at
the
base
but
upwards
they soon become thin. The
Fig.
274.
Polysiphonia
ma-
crocarpa Harv. a, summit of
a filament with young
cy-
stocarps.
b, transverse
sec-
tion of a filament,
(a, about
200:1,
b,
150:1).
Fig.
273.
Polysiphonia
macrocarpa
Harv.
Part of a female
plant. (About
16:1).
filaments are about 100^ thick, but both
thinner and thicker ones are to be found.
The length of the cells in these filaments
is
rather
variable.
Generally
they
are
about one
and
a
half to twice
as long
as they
are
broad, but
often
they are
three
to
four
times
as
long
or
even
longer.
Upwards
the
filaments
taper
gradually
and
in
the upper ends they
are only 20
25 //
thick.
The
erect
filaments
are
often un-
branched
at
their base.
If we examine
such a young filament in vigorous growth
18*
276
we
find
it
quite
destitute of trichoblasts
(comp.
Fig.
272);
it
is
straight
and
its
diameter increases
rather
quickly down-
wards
from
the small apical
cell, which
is
constantly divided by horizontal walls.
Upwards the filaments are rather richly
ramified on
all sides. The branches
issue
without any connection with the tricho-
blasts (Fig. 274). The distance between the
trichoblasts
or branches
varies
consider-
ably,
sometimes
these
issue
from
each
joint, sometimes 1
3 segments
are bare.
The trichoblasts are richly developed
in some specimens, more sparingly or not
at
all
in
others.
The
tetrasporangia
(Fig.
275 b)
are
found
in
long
rows
at
the ends
of
the
filaments.
These
are
mostly
undivided,
sometimes
forked.
The
segments
con-
taining the tetrasporangia are spherically
swollen, about 80^
broad.
The
antheridial
stands
of
the Potysiphonias
are,
as
is well
known, formed by the
trichoblasts, and with regard to these
or-
gans
the
present
Polysiphonia
belongs
to
the
group
of
species
(e.
g.
atrorubescens,
fastigiata,
scopulorum
etc.)*) in which the whole trichoblast is trans-
formed, not having even a sterile end, as is for
example the case in Polysiphonia urceolata**).
They
(Fig
275 a)
are
cylindrical
in
shape,
with
an
obtuse
apex,
about
400500 n
long
and
100110 ^
broad.
The
pedicel
bearing
the
antheridial
stand
consists
of
two
cells,
the
short
basal
cell always found
in
the
trichoblasts, and a longer cylindrical
one.
The cystocarps originate from the second
of
the
trichoblast,
as
is commonly
the
Fig. 275. Polysiphonia ma-
crocarpa Harv.
a, filament
with antheridial stand;
b,
upper
end
of
tetrasporic
filament
(a, about 360:1;
b, about
50:1).
Fig. 276. Polysiphonia
macrocarpa
Harv. A
nearly ripe cystocarp.
(About
70:1).
*)
Cfr. THURET
et BORNET, Etudes phycologiques,
p. 86.
'*)
Gfr. ROSENVINGE, L. KOLDERUP,
Sur
les organes piliformes des Rho-
domelacees
(Overs,
k. danske
Vidensk.
Selsk.
Forhandl.
1903,
p.
450,
fig.
2).
277
case
in Polysiphonia*}. When
fully developed
they
are
urceolate
in shape
(Figs. 273, 276), with a broadly hemispherical base tape-
ring
gradually
upwards,
the
apex
prolonged
into a rather
long
neck. They
are
about
250
;j. long
and
190
/j. broad. As to their
shape they agree very well with KUTZING'S
figure,
1.
c.,
fig.
c.
This plant
is
evidently
in
several respects
nearly related to
P. sertularioides**) but
this
species
has
branches
in the
axils
of
the
trichoblasts
as described by KNY***) and FALKENBERG,
1.
c.,
p. 122, pi.
I,
figs.
1
16,
so that Polysiphonia macrocarpa, owing to
the lack
of
axillary branches, (provided that my plant
is
rightly
referred
to
this
species)
is
easily separated from
it.
It has been found with tetraspores, antheridia and cystocarps
in the months
of January and February.
St. Croix:
Christiansted's Lagoon, Salt River,
Krause's Lagoon.
St.
Thomas: Bovoni Lagoon.
St. Jan: Coral Bay.
Geogr. Distrib.
:
Atlantic
coast
of Europe
and
Africa from
Great
Britain
to Morocco. West
Indies.
6.
Polysiphonia ferulacea Suhr,
J. Ag.
J. AGARDH, Spec. Alg
,
vol.
II, pars
III,
p. 980.
Polysiphonia
breviarticulata Harv., Nereis Bor.-Am.,
p. 36,
tab. XVI B.
This
plant
was
found
growing among
other
algaB
forming,
together with
these, entangled
masses.
It
is a very coarse and ro-
bust plant.
It has
creeping
basal
filaments
(Fig. 277 a)
fastened
to the
surrounding
algaB by means
of
numerous
hapters. The
hapters
are commonly
short,
but vigorous, with
thick
walls, and end
in
a small
lobed
disc.
The diameter
of the
cylindrical stem
of the
rhizoids
often
reaches
a
length
of
more than 100 ^. The
basal
filaments
are
about
HOO
/j.
thick, sometimes even 400
/u or more.
The peripheral walls
are very thick
(lat. about 8^);
also the walls
between
the
cells
are
proportionally
substantial.
The
cells
are
about
130
fj.
broad
and
100 n
long. The
hapters
often
issue
in
pairs
side
to side,
a
single one from each
of the
pericentral
cells
below.
On
their upper
side these
filaments carry the erect branches
*J Gomp. ROSENVINGE, L. KOLDERUP, Bidrag
til Polysiphonias
Morfologi,
Bot.
Tidsskr
,
Bd.
14,
1884,
p. 23.
**)
Cfr. BORNET, Ed. Les Algues de P. K. A. SCHOUSBOE, p. 306.
In Sylloge
DE-TONI has P. macrocarpa as merely a synonym of P.
sertularioides.
***} KNY, L
, Cber Axillarknospen
bei
Florideen,
p. 105,
pi.
II,
figs. 14.
278
(Fig. 277 c).
These
are about
200
250 //
thick, and
the
cells are
nearly quadratic, mostly somewhat shorter than long, about 100 p
broad and 85^
long.
The erect branches are ramified on all sides. The branches grow
out to filaments
like
the mother branch, some
of them
shorter,
some longer. Rhizoids may issue from every cell in the filaments, by
means
of which they attach themselves to the neighbouring plants
Fig. 277. Polysiphonia ferulacea Suhr,
J. Ag.
a, base of a plant,
b, summit
of the same basal filament,
c, basal filament
with
erect filament,
d, transverse section
of a filament.
(a, about 20:1;
b,
250:1;
c, 20:1;
d,
60:1).
or other substratum, and when
so
attached new erect
filaments
may issue from them.
The branches are produced without any connection with the
trichoblast
(Fig. 278 a). The
last mentioned
are
copiously devel-
oped and
generally quite
cover
the upper end
of
the
filaments,
but they are not very persistent and drop
early. A trichoblast
is
developed upon each segment with a YI divergency.
The tetrasporangia
occur
in
the summit
of the filaments
in
long rows, a single one
in each segment forming together a screw
(Fig. 2786). The tetrasporangia are about 60^
thick.
279
The antheridial stands
(Fig. 279) are formed by the first
side-
branch of the trichoblast. They are rather thick, subcylindrical, with
a nearly spherical, thick-walled, sterile,
apical cell; sometimes two
are found. The fertile part is up to 200 u long and 60 u. broad. The
fertile trichoblasts
are found
in the summit
of the filaments. The
antheridial
plants
are
somewhat
more
slender than
those
with
Fig. 278. Polysiphonia ferulacea Suhr,
J.-Ag.
a, summit
of a filament;
of "some
of the trichoblasts the basal cell
is drawn
only,
b, summit of a plant with tetrasporangia.
(About
180:1).
tetrasporangia
and
cystocarps,
the
diameter
of
the
vegetative
filament reaching only about 150 ju.
200^.
The cystocarps
(Fig.
280)
are
large, nearly
spherical, with a
short
stalk. They are about 350 p. long and broad.
I have compared my plants with specimens belonging to the
Botanical Museum,
Copenhagen,
collected by LIEBMAN
at
Vera
Cruz and determined by
J. AGARDH. AGARDH had at first referred
these specimens to Polysiphonia breviarticulata but
in
Species Al-
garum,
vol. II, pars III,
p.
981, he
alters
this determination and
refers LIEB MAN'S plant to
P. ferulacea.
280
My
specimens
agree
in
the
main
with
the Mexican
plant,
only they are much more vigorously and robustly developed. The
Mexican plant has more slender filaments and, moreover a taller
thallus than mine, and
agrees better with HARVEY'S
figure
(1.
c.).
Fig. 279.
Polysifthonia ferulacea Suhr,
J. Ag.
Summit of a plant with antheridial stands. (About
125:1).
That the specimens collected by me are so robustly developed
is most probably due
to the exposed
places
in which they grew.
Thus they were found upon the
coral
reef connecting the
Hurri-
cane
Island
with
St. Thomas, a
locality, and
the
peculiar
algal
vegetation
of which
I have mentioned earlier*).
P. ferulacea forms
here, together with
Caulerpa
racemosa, L
reducta, Cladophoropsis
membranacea and a few other
alga?,
low, compact
patches which
are
all the more strongly felted together inasmuch as most of these
algse occurring here are able to develop haptera from nearly every
*) B0RGESEN,
F., An ecological and systematic account
of the Caulerpas
of the Danish West Indies
(Kgl. danske Vidensk. Selsk. Skrifter,
7. Rk.
Naturv.-Mathem. Afd. IV, 5, 1907,
p. 346).
281
Fig.
280.
Polysiphonia
ferulacea
Suhr,
J.
Ag.
Part of
a filament with a nearly ripe cystocarp.
(About
125:1).
part
of
their
thallus,
this also being the case
with
P.
ferulacea
as
mentioned above.
St.
Thomas:
The
reef
between
the
Hurri-
cane
Island and
St. Tho-
mas.
Store
Nordsidebugt.
St. Groix: Northside.
Geogr.
Distrib.:
Mexico, West
Indies, Au-
stralia.
Sandwich
Islands.
Digenia Ag.
1.
Digenia simplex
(Wulf.) Ag.
AGARDH, G., Spec. Alg.,
p.
389.
Syst.
p.
194.
J.
AGARDH,
Alg.
Medit.,
p.
147; Spec. Alg.,
vol.
II, pars
3, p. 845. HARVEY, W. H.,
Nereis
Bor.-Am.,
part
II,
p.
30.
FALKENBERG,
P.,
Rhodomelaceen,
p.
159.
pi.
9,
figs. 25- 29.
Conferva
simplex
Wulf.,
Cryptogama
Aquatica,
p. 17.
Cfr. DE-TONI,
Sylloge Alg., vol.IV,
p. Ill,
p.
963,
where more synonyms are named.
Regarding
its anatomy and morphological
building upon the whole
I refer to FALKENBEEG'S
exhaustive
description
1.
c.
Digenia
simplex
occurs
both
in
shallow
water and rather exposed places
and
in
deep
water.
The
different
localities
determine
to
a
large
extent
the development
of
the
plant;
in
the
first mentioned
places
the plant
is robust,
of
low growth, about
5
6 cm
high and much
ramified,
in
deep water
on
the
other
hand
I
have gathered specimens about 20 cm high and
nearly unbranched.
Its
stiff,
tough
stem
is
a very
attractive
growing place
for numerous
small
algaB which
commonly cover
its
thallus
to such an extent
that only the
quite young tips
are
free.
Fig.
281.
Digenia
simplex (Wulf.) Up-
per end
of branch
with
tetrasporan-
gia. (About
125:1).
282
Specimens with tetrasporangia were found. The tetrasporangia
occur
in
the
upper end
of
the branchlets with
definite growth.
These grow thicker in the fertile part, the whole branchlet assuming
thereby a clavate appearance
(Fig.
281).
The
tetrasporangia are
placed
in
screws, one
in
each
segment. They are about 80^
in
diameter. The specimens with these
organs were gathered
in
Ja-
nuary and February.
As mentioned
above
this
plant
is
gathered both
in shallow
water and
in deep water down to a depth
of about
30 meters.
It
is a rather common species along the shores of the islands.
Geogr. Distrib.
: Seems
to occur
in nearly
all warm
seas.
Bryothamnion
Kiitz.
1. Bryotkamnion triquetrum (Gmel.
) Howe.
HOWE,
M.
A.,
in
Journal
of
the New York
Bot.
Garden,
vol. XVI,
1915,
p. 222.
Bnjothamnion
triangulare
Ktitz.,
Spec.
Alg.,
p.
842.
J. AGARDH, Spec.
Alg.,
vol.
II,
p.
Ill,
p.
850.
FALKENBERG,
Rhodomelaceen,
p.
172,
tab.
19,
figs. 3233.
Fucus
triqueter
S. G. Gmelin,
Historia
Fucorum,
1768,
p.
122,
tab.
8,
fig.
4.
Fucus triangularis J. F. Gmelin in Linne", Syst. Naturae, Editio 13, p. 1383.
TURNER,
Fuci,
tab.
33.
Alsidium triangulare
J. Ag.
in
Linnsea,
vol. XV,
1841,
p. 28. HARVEY,
W. H., Nereis Bor.-Am., Part
II,
p. 15,
tab. XIII.
A.
As pointed
out by FALKENBERG
it
is rather
difficult to ex-
tract
the summit
with
the
young
growing
point
of
this
plant
from
the surrounding
branchlets which
quite
cover
it, but
after
some
attempts
I
succeeded
in removing one,
of which
the
ac-
companying drawing
is
a
copy.
This
agrees
well
with FALKEN-
BERG'S description. From the cup-shaped top-cell disc-formed
seg-
ments
are gradually cut
off, which
afterwards
again
are divided
by
vertical
walls. From
every
second
segment
a
trichoblast
is
developed. The trichoblasts are placed in a screw line with a diver-
gency
of
Vs;
in
fig.
282
the
uppermost
tips
of
the trichoblast
marked 4
are
seen
only,
as
this
trichoblast
stands
behind
the
main
axis and branch
5.
The
trichoblasts
are
rather
poorly
developed,
only
forked
once above the basal cell, and the two filaments, when fully devel-
oped, consist of 4 cells only; the nethermost
cells are cylindrical
barrelshaped, the uppermost
short, subspherical
; the diameter
of
283
the
cells
is about
12 // long;
they have rather thick walls. Upon
the
branchlets
the
trichoblasts
are much
smaller, the
filaments
above
the
forking
consisting
of a
single
cell
only.
In
his plant
FALKENBERG
did
not
find
more
than two
to
three
cells
in the
filaments
of the
trichoblasts.
From the basal segment of each trichoblast a branch is devel-
oped.
As
is pointed
out by FALKENBERG
this
is placed
quite,
or
very
nearly
in
the manner of an
axillary
branch.
These
axillary
branches
in-
crease very
quickly and
as-
sume
at an ear-
ly stage the car-
tilaginous consi-
stency
of
the
whole
thallus.
When young
they are inward-
ly bent, shelter-
ing the summit
of the plant. The
trichoblasts
are
shed
early
and
leave
no
scars,
their place being
quite
effaced by the
cortical
layer which
is most abundantly de-
veloped just
at the base of the branches. Most
of these branches,
after having reached
a certain
length, stop their development and
become
the
spiny
branchlets
characteristic
of
this
species
(Fig.
283). Now and
then one
of
these branchlets
assumes continuous
growth and grows out like
the main filaments.
The
ramification
of
the branchlets
takes
place
quite
in the
same manner with the exception only that,
as mentioned above,
the growth
is soon stopped.
My material contained
sterile
plants only.
Bryothamnion
triquetrum
is
fairly common
in
shallow water
in
sheltered
as
well
as somewhat
exposed
places;
sometimes
it
grows
in
rather
large
societies.
Further
it
is
also
dredged
in
Fig. 282. Bryothamnion triquetrum (Gmel.) Harv.
16, successive generations of branches and trichoblasts.
The
cells
in
the basal
part are brought somewhat in
disorder by the preparation and the branches and tricho-
blasts, also, are not quite in their exact place. (About 330:1).
284
Fig.
283. Bryoihamnion
trique-
tru/it (Gmel.) Howe. Part of a
plant. (About 3:1).
rather deep water
at
a depth
of
20
meters
or
more.
The
plants
taken
from deep water are
slender and
are
not much ramified, those from
shal-
low water are more robust and richly
ramified.
This species
is
rather common along
the shores of the islands.
Geogr. Distrib.: West
Indies, Bra-
zil, Atlantic
coast of
Africa.
Bryothamnion Seaforthii (Turn.)
Kiitz.
KUTZING,
Phycologia
gener.,
p.
433,
tab. 52,
fig. 11; Spec. Alg., p. 842. AGARDH S
J.,
Spec.
Alg.,
vol.
IL
pars
III,
p.
848.
FALKENBERG,
P.,
Rhodomelaceen,
p.
174,
tab.
19,
fig. 34.
Fucus Seaforthii Turner, Fuci, pi. 190.
Thamnophora
?
Seaforthii
Ag., Spec.
Alg.,
p.
227.
System.,
p.
240. Mon-
tagne
in Ramon
de
la
Sagra,
Hist.
Cuba,
Bot.,
p.
56,
pi. V,
fig.
1.
Alsidium
Seaforthii
J.
Ag.
in
Linnsea, vol.
15,
1841,
p. 28.
Cfr. DE-TONI, Sylloge Algarum,
vol. IV, p. 975, where more synonyms
are named.
The
specimens
found
are
all
distichous.
I have
not seen
any specimen like forma
imbri-
cata
J. Ag.
Regarding the development
of
the thallus FALKENBERG de-
scribes
it
as
follows:
"Haupt-
und Seitensprosse produciren, so
viel
ich
gesehen
habe, nur un-
mittelbar
vor
ihrem
Erloschen
schraubig gestellte Blatter ohne
Achselsprosse;
die Seitensprosse
ihrerseits
scheinen
stets
ohne
vorhergehendes
Tragblatt
zu
entstehen, so dass bei den zwei-
Fig. 284. Bryothamnion Seaforthii
(Turn.)
Kiitz. 16, successive gene-
rations of branches and trichoblasts;
at
1
the
first
segment
of
the main
stem just begins to grow out; 2, shows
a young trichoblast; 3 and 4, tricho-
blasts with axillary branches;
at the
base
of
branch
5
the
scar
of
the
trichoblast
is
seen.
(About
300
: 1).
285
Fig. 285. Bryothamnion
Seaforihii
(Turn.)
Kutz.
Part of the thallus.
(About 4:1).
fellosen
generischen
Zusammen-
horigkeit
mit
B.
triangulare ange-
nommen werden
muss,
dass
die
schwach entwickelten
Blatter von
B.
triangulare
hier
grosstentheils
ganz abortirt sind. Haufig abortiren
tibrigens
selbst
die Blatter an den
erloschenden
Spross-Spitzen
mehr
oder weniger."
This has not been
altogether
confirmed
by
the
ex-
amination
of my material.
The
figure
284
shows
the
growing summit removed from the
surrounding protecting branchlets.
From
this
it
is
evident
that
the
growth
of Bryothamnion Seaforthii
takes
place
in
a very similar way to
that
of
Bryothamnion
tri-
quetrum.
As
in
this
species, trichoblasts
issue from every second
segment;
the trichoblasts
are once forked, each
of the filaments
consisting
of 4
cells,
and
are upon
the
whole much
like
those
found
in Br. triquetrum; the only difference seems to be that the
cells
are much
shorter.
On
the
other hand
their
diameter
is
somewhat
longer,
about
20
i>.\
sometimes
one
of
the
filaments
bears a short
sidebranch.
But
while
in Bryothamnion triquetrum
the
trichoblasts
are placed in a screw line round the summit with
a divergency of
120,
in
the present
species
they
are
placed
di-
stichously with
a
divergency
of
180. From
the
basal
cells
of
each
of the trichoblasts an axillary branch
issues. These branches
grow quickly and are bent inwards over the young summit.
I can
not
say
how
far
the
trichoblasts
are
placed
exactly
with
a
diver-
gency
of 180
or
some
smaller variations are to
be found
;
in every case
some
small
oscillations
seem
to
be
present
as
the branches alternately
place their summits over
f
,z,--/rr
v-t.
or under
the
following
Fig. 286. Bryothamnion Seaforthii (Turn.) Kutz.
Transverse section of the thallus. (About 30
: 1).
branch.
286
Most
of
the
branches
soon
stop
their
growth
and
become
short spiny branchlets
(Fig. 285), a few assume continuous growth
like the main filament. As pointed out by FALKENBERG the short
branchlets
grow
somewhat
longer than
those
of
Bryothamnion
triquetrum;
they
have
generally
from
four
to
six side-branches,
and
the nethermost
are
again
ramified,
having
three
to
four
spiny ramuli, while the uppermost
are reduced to
spines.
At the ends
of these
spinelike
branchlets, in any case
in the
younger part
of the
plant, we
find a few
trichoblasts. These are
often considerably developed, being dichotomously ramified
seve-
ral times. As all the filaments in these trichoblasts are erect and run
together, nearly
parallel,
they form a rather dense bush. One
of
the
largest
trichoblasts
I have
seen had
in
the basal part
cells
about 35
[j.
thick. These
cells were nearly spherical in shape, being
much narrowed
at the
cross wall; the
cells taper evenly upwards
towards
the summit
of
the
filaments,
the
uppermost were only
6
7 fj. thick. A transverse section
of the thallus shows 8
9 peri-
central
cells
with
a
thick
parenchymatic
tissue
on
both
sides
(Fig. 286).
The material gathered was
quite
sterile.
This plant was dredged in rather deep water about 30 meters.
A
single specimen was found washed
ashore.
It seems not to be common on the
shores
of the
islands.
St. Jan:
Of! Annaberg and
off
America
Hill.
St. Thomas:
Near
Thatch C?y. St. Croix: Sandy Point (washed ashore).
Geogr. Distrib.: West
Indies, Mexico,
Brazil; coast of Guinea.
Subfam.
4. Herposiphonieae.
Herposiphonia Nagl.
1. Herposiphonia tenella
(C. Ag.)
Nagl.
NAGELI,
C., Herposiphonia
(in SCHLEIDEN und NAGELI,
Zeitschrift fur
wissenschaftl.
Botanik,
3
/ 4 .
Heft, Zurich 1846,
p. 238,
tab. VIII.). AMBRONN,
H.,
in
Bot. Zeitung,
1880, p. 197,
pi.
IV. FALKENBERG,
P., Rhodomelaceen,
p.
304.
Hutchinsia
tenella
Ag., Spec.
Alg.,
vol.
II,
p.
105.
Polysiphonia
tenella
J.
Ag., Algae Mediter.,
p.
123;
Spec.
Alg.,
vol.
II,
p.
Ill,
p. 919.
In
describing the plant
I
at
first
refer to specimens collected
at
St. Groix. These specimens (cfr. Fig. 287) seem
in
all
essentials
to agree with the descriptions
of AMBRONN and FALKENBERG.
287
As
is well known, the plant has a decumbent, creeping main
stem,
in my specimens with
for the most
part nine to ten
peri-
central
cells
(Fig. 288 b}. The length
of the diameter
of the stem
is
somewhat variable,
about
170^
long, and the
length
of
the
segments about 350 //.
There
is no
cortical layer to be found.
Fig. 287. Herposiphonia
tenella
(C. Ag.)
Niigl.
Part of a plant.
(About
30:1).
The young summit
of
the stem
is
curved
upwards and
in-
wards, turning
its convex side to the substratum. The longitudinal
growth is procured by means of an apical cell from which segments
are cut
off. From
these even before
they
are divided the bran-
ches
or branchlets begin
to grow out; then the segments
are
di-
vided
in the central and pericentral cells. FALKENBERG gives
fine
illustrations of the division of the summit
(1.
c., pi. Ill, figs. 14, 15).
From
the
pericentral
cells on the ventral
side
of the stem a row
288
of rhizoids break out
(comp. fig. 287).
They
issue from the
fore-
most end
of each
cell.
These
rhizoids
are
often
of
considerable
length, up to 1mm or more, but seldom
ramified. They have no
walls and do not generally end
in a
disc. Only a few have been
found with a rather
irregular
disc,
like
those
described by AM-
BRONN,
1. c., p. 211. From the mother-cell the rhizoids are separated
by an oblique
wall.
The
cylindrical stem
of
the
rhizoids
is about 30
/j.
thick.
Upon
the
dorsal
side,
the
main
stem
bears two
kinds
of
branches, some with
in-
definite
growth able to grow out to a main
filament
like
the
mother
stem,
and
some
with limited growth. In the following we may
call them respectively branches and branch-
lets.
The
branches
with
continuous
growth
are
placed
alternately on
both
sides
of the
main
stem, one upon each
segment, and
in
such a way
that
there
in
the typical
form
are
always
three
segments
between
those
bearing the branches
(Fig.
287).
Upon the upper dorsal side of these three
segments the branchlets with definite growth
issue.
These
are
placed
singly,
that
is,
a
single
one upon each segment,
in two rows
and
in
such a way that
after
each
branch
with
continuous
growth
a
branchlet
is
de-
veloped from
the opposite
side
of the stem;
if this
branch
is
found
on
the
left
side
of
the stem, the
following
branchlet
is
placed
on
its right
side, the next one
is then found on the left
side and
the
third again to the
right, then
follows a branch on
the
right
side and
so
on. AMBRONN,
1.
c.,
pi.
IV,
fig. 17 and FALKENBERG,
1.
c.,
p. 303 have given
clear diagrams
of the arrangement
of the
branches and branchlets.
At
first
the branchlets
are much more
developed
than the
young
branches.
The young
branchlets
are much curved
in the
opposite direction to that of the summit of the main stem, bending
down over the
latter as a protecting cover (comp.
fig.
287).
The branchlets
are
never ramified;
at their
base they have
but few pericentral cells
(4
5, comp. 288 a), upwards the number
Fig.
288.
Herposipho-
nia tenella(C. Ag.)Nagl.
, branchlet with
te-
trasporangia. b, trans-
verse
section
of
the
thallus. (a, about 90:1;
b, about
80:1).
289
of these soon increases
in
the following
segment,
until the same
number
is
reached
as
found
in
the main
stem. The number
of
segments
in
each
branchlet
seems
to
vary
considerably;
in my
plants
the branchlets
are
rather
short, having
only 10
13
seg-
ments. AMBRONN
on
the
other
hand
(1.
c., p. 211) has found up
to 40
in each
branchlet.
The segments
in my plants were about
60
fjL
long and
the
diameter
of
the
branchlet
about
45 //. The
length
of the whole branchlet was about 1mm.
290
of
the
branches
and
branchlets,
I
at
first
took
it
for
Herposi-
phonia
secunda.
But
after
having
examined
it
in
more
detail
I have
arrived
at
the conclusion
that
it
is nothing
else
than a
form
of H. tenella.
The
figure
(Fig. 289) shows a part
of
this plant.
Quite a peculiar
feature
of
this
plant was
to
be
found
in
the
facts
that
the
ordinary
number
of
segments
between
the
branches were not maintained, that the branchlets were wanting
in
some
segments, leaving
the
latter bare, and
finally that the
branches
were
often
quite rudimentary.
This
is
clearly seen in
the diagram
of the same part
of the plant
as shown
in Fig. 289.
Beginning from the
left end
of the
figure we
at
first have a
branchlet
on
the
right
side
and
one
on the
left,
then
a
rudi-
mentary
branch
on
the same
side;
then
follow three
segments
with
branchlets and one with
a
branch
placed
quite
in accord-
ance
with
typical H. tenella.
But then we
have
a bare segment
and
after that one with
a branchlet placed on the left side, then
follows
a segment with a branch
also
to the
left; then again we
have
a
bare
segment,
then
one
with
a
branchlet to the
right,
and then a segment with a branch on the same side. The arrange-
ment
of
branches,
branchlets
and
bare
segments
in
these two
last mentioned
groups
of segments
agrees very much with
that
found
in H. secunda,
the .only
difference being that
in
the
true
Herposiphonia
secunda we
have
two
consecutive bare segments,
whereas
in the present case there is a single one only. After these
groups
followed
three
segments
with
branchlets
and
one with
a branch placed
in the ordinary way as found
in H. tenella, and
then
again
a group
ol segments deviating
as
to their branching
from the type,
like those already described. As pointed out above,
it cannot be denied that this abnormal branching largely
recalls
that found
in
H. secunda, a modification which FALKENBERG has
also noted
in this species
(cfr. FALKENBERG,
1.
c.,
p. 307, pi. 3,
fig.
11). But
as other parts
of the plant were branched in accordance
with the typical form
I have no hesitation in referring my plant
to
H.
tenella.
Yet
in
another
point
this
plant
differs
from
the
true
H.
tenella,
recalling H. secunda,
viz.
in
the
very short
seg-
ments,
these 'being much shorter than their breadth,
for instance
in
the branchlets:
length
=
= about
25//,
breadth
=
= about 35 //.
FALKENBERG
discusses
this
question
ho\v
far
Herposiphonia
secunda
really
is
to
be
considered
as
an
independent
species
or
is
nothing
else than
a
form
or
variety
of H. tenella.
Leav-
291
ing
at
first
the
different
ramification
of
the
two
plants
out
of
consideration,
he
points
out
that
according
to
the
diagnosis
of
the two
species
the
following
two
differences
are
the
only
found, namely:
1, the
short
segments
of Herposiphonia secunda
and
2,
the
lesser number
of
the segments and
sporangia
in the
branchlets
of H. secunda.
As to the
first mentioned
difference he
remarks
that
this
is
of no great importance,
as he has found
in
all other respects a quite typical form
of
tenella having altogether
the same habitus as that of H. secunda*}. And regarding the other
point
I need
only
refer
to my remarks
above
concerning
the
small number
of segments and
of tetrasporangia developed in my
specimens.
But when FALKENBERG
nevertheless
regards
the two
plants as separate
species, he bases
this upon the most
essential
difference between them,
viz.: the heterogeneous
arrangement
of
branches and
branchlets,
pointing
out
that he has never found
the ramification
of H. tenella
in typical specimens
of H. secunda.
But
as to
this
point
it cannot be denied that the above
descri-
bed specimens,
actually having
the
ramification
of
both plants,
greatly weakens
the
supposition
that
the
two
plants
are to be
regarded
as
two
distinct
species.
Most
probably,
therefore, H.
secunda
is nothing more than a reduced form or variety of H. tenella.
Curiously enough the plant coming near to secunda was found
intermingled with
a quite normally branched
var.
typica
of Her-
posiphonia
tenella
the
contrast between the two forms being en-
hanced by the
fact
that
it was provided with
slender, long seg-
ments, much longer than those found
in the form from
St. Croix
;
for instance
in one specimen the segments
of the main stem were
100 n broad and 280 /j
long, and in the branchlets about 50^ long
and 30
tu broad.
FALKENBERG
too
states
(1.
c., p. 308)
that
he
found
"beide
Arten
in Neapel das ganze
Jahr hindurch an den
gleichen Stand-
orten
neben
einander". This seems to show that the two plants
in question
are
in
all
cases
in
reality more
or
less
strongly
dif-
ferentiated
forms,
and
are
not
developed
by
the
influence
of
different
external conditions.
*) In
this connection
I
also want to
refer to the form which ASKENASY
in "Forschungsreise
S. M. Gazelle". IV Theil, Botanik, p. 50, pi. X,
figs.
14
17 has described and figured as Polysiphonia Calothrix. From
this it
seems
to me beyond
all doubt that the plant in question
is our plant
of which ASKENASY
has found
not
only
the
typical
tenella
but also
secunda. According to the figures both forms have short segments.
19*
292
Both
plants
are
found
near
the
shore to
a depth
of a few
feet
only and
in
rather sheltered
localities.
Tetrasporangia were
found
in January.
St. Croix: Protestant Cay
at Christiansted; St. Jan: Cruz Bay.
Geogr. Distrib.: Mediterranean Sea, Morocco, West Indies, Bermuda.
Fig. 290. Dipterosiphonia
dendritica
(Ag.) Falkenb.
Part
of the thallus showing the ramification. (About
80:1).
Dipterosiphonia Schmitz et Falkenb.
1.
Dipterosiphouia
dendritica (Ag.) Falkenb.
FALKENBERG,
P., Die Rhodomelaceen,
1901,
p. 324.
Hutchinsia dendritica Ag., Systema,
p. 146; Species Alg., vol.
II,
p. 104.
Polysiphonia dendritica
J. Agardh,
Species Aig
,
vol.
II,
]>.
3, pag. 916.
Of this beautiful, small plant a few specimens were found atta-
ched to Cladophora
fuliginosa.
Referring for further details
to the
293
above quoted description of FALKENBERG,
I
shall here only men-
tion
briefly the specimens found
(Fig. 290).
What
mostly
characterizes
this
genus
is
the
dorsiventrally
built, creeping main filaments, from which the exogenous branches
are formed
alternately
in
pairs on both
sides;
of these branches
the lower one
becomes a
short, unbranched branchlet, while the
other, the upper, becomes ramified
in a similar way as the mother
filament.
Dipterosiphonia
dendritica
has
5
pericentral
cells which
arc
mostly arranged
in rather distinct rows. Of these
5
cells
in each
segment,
the
two
are
placed
on the somewhat
flattened,
lower,
Fig. 291. Dipterosiphonia dendritica
(Ag.) Falkenb.
o, summit of a filament seen from above,
b, transverse section of the thallus.
(About 180:1).
ventral
side, while the three others
are found on the upper dor-
sal
side
(Fig. 291 b).
The main stem
is about 115 //
thick.
From the ventral
cells
vigorous short rhizoids
issue; these end
in
irregularly lobed
discs
by means of which the plant is fixed to the host plant (see Fig. 290).
Of
the
branches
placed
in
pairs
the
one
is,
as
mentioned
above, developed
like the main stem.
It
is
ramified
in the same
way but
is
generally
less vigorous.
Its
branches
are commonly
unbranched
and
it
stops
in
most
cases
its
longitudinal growth
after having
developed
5
6
pairs
of branches; but
occasionally
under favourable conditions
the branches grow out to
real main
stems
like the mother filament (Compare
Fig. 290).
The
short branchlets remain undivided.
Sometimes they are
short
or quite rudimentary,
sometimes
they grow to a consider-
able
length. They are
about
60
,
thick. A few trichoblasts were
found upon the
short branchlets.
By reason
of the greatly varying development of the branches
and branchlets
their
original arrangement
in
pairs
is often much
294
effaced
in
older parts
of the
thallus.
In the young parts, on the
other hand,
it
is always very
distinct (comp. Fig. 291 a).
Upon the specimens found only two tetrasporic stichidia were
present. The tetrasporangia
are formed in the ends
of the ramuli.
The
fertile part consists
of
3
4 segments.
It
is so much swollen
that,
as
pointed
out
by FALKENBERG,
1.
c.,
"die
sterile Stamm-
basis
dagegen
als
diinner
Stiel
scharf
abgesetzt
erscheint". The
fertile part
is about 80 //
thick.
With
regard
to
the
figures
hitherto given intended to por-
tray this
species, they
are
all more
or
less unhappy.
I
refer to
FALKENBERG'S statement concerning this matter.
Dipterosiphonia dendritica was found growing on
a rather ex-
posed place and
in shallow water.
Besides upon Cladophora
fuli-
ginosa
some
other
specimens
have
been
found
upon
Laurencia
papillosa.
St. Croix.: White Bay.
f
Geogr. Distrib.:
Brazil,
Australia.
Subfam.
5. Lophosiphonieae.
Lophosiphonia Falkenb.
1. Lophosiphonia obscura
('Ag.) Falkenberg.
FALKENBERG,
P., Rhodomelaceen,
p. 500.
Hutehinsia obscura Ag., Spec. Alg.,
p. 108.
Polysiphonia obscura
J. Ag.,
Algae Mediterr., p. 123; Spec. Alg., vol.
II,
pars
III,
p. 943.
In
the few
specimens
I have
collected
the number
of
the
dericentral
cells was
about
11
12.
There was no
cortical layer
present.
The
plant
forms
low
tufts
about
1
3 cm high. The basal
creeping filaments
are
fastened
to
the substratum by means
of
numerous
short
hapters
(Fig. 292 a), a
single one emerging from
each pericentral
cell, but often 23
side by
side from each
seg-
ment
(Fig. 292 b). The hapters end
in
irregularly lobed
discs.
The diameter
of
the creeping
filaments
is about 150 p.
long.
From
the upper
side
of
the creeping filaments branches emerge,
arranged more
or less dorsally, the distance between them varying
much. Some
of
these
branches
bend
downwards
and
fix them-
selves to the substratum
like the mother filament, but the greater
part grow upwards.
295
While the creeping filaments
lack
trichoblasts, these are pre-
sent
in
the summit
of
the
erect
filaments
(Fig.
293).
In some
specimens
taken
from
exposed
places
these
were
abundantly
developed,
in others
taken
from
sheltered
spots
they were very
scarce, often quite wanting.
The
trichoblasts
are developed
in the upper end of the bran-
ches,
and, when they
first appear, each segment often bears
one.
As pointed out by FALKENBERG they are placed with a divergency
Fig.
292.
Lophosiphonia
obscura
(Ag.)
Falkenb.
a, basal
part
of
plant;
b,
part of a basal filament showing scars after rhizoids placed in rows,
c, trans-
verse
section
of
the
thallus.
d, summit
of
a
filament,
(a, about
30:1;
c,
about 200:1;
b and
d, about 450:1.)
of about Y4 -
The
trichoblasts
are rather
robust with somewhat
thick walls; near the base
of the trichoblasts the
cells
are about
28^ thick
and
the
walls
of
the
cells
about
4/^. Most probably
the
trichoblasts serve as a protection
for the young
tips, not only
against
the
strong
light,
but
also
against the
violence
of
the
waves.
The
erect filaments
are more or
less branched
; the branches
have no connection with
the
trichoblasts
(Fig.
293).
The upper-
most young
summits
of
the branches
are much curved, turning
their concave
side towards the mother branch.
The tetrasporangia
(Fig.
294) are
found in shorter
or longer
296
series,
a
single
one
in
each
segments;
they
are
mostly
placed
rather clearly in screws. The tetrasporangia are about 60 p broad.
The
plant
grows
in
shallow water
near
the
shore
and has
been found both in sheltered as well as in more exposed localities.
Fig. 293. Lophosiphonia obscwa
(Ag.) Falkenb. Upper end of a
filament. (About 100:1).
Fig. 294.
Lophosiphonia obscura (Ag.) Fal-
kenberg. Part
of a plant with
tetraspores.
(About 20:1.)
St. Croix:
Christiansted's
Lagoon, White Bay. The
plant
has been
collected
earlier by 0RSTED on the shores
of
this
island.
Geogr. Distrib.
: West
Indies, Mediterranean Sea and warmer parts
of the Atlantic Ocean.
297
2. Lophosiphonia
cristata Falkenb.
FALKENBERG,
P., Die Rhodomelaceen,
p. 499.
The West
Indian
plant
(Fig.
295)
seems
to agree very well
with
the
plant
from
Naples,
to
judge by
the
description
and
figures
of
FALKENBERG.
However,
regarding
the number
of
the
pericentral
cells
a
difference
is
noticeable,
as
FALKENBERG
has
found
6
8
pericentral
cells
in
his plant, while mine has 9
10,
now and then
in the
erect branchlets even more
(Fig.
296).
Fig.-295- Lophosiphonia
cristata Falkenb. Part
of a plant.
(About
20:1).
In accordance with the description
of FALKENBERG our plant
has
a
creeping
rhizome-like
stem
with
indefinite
growth,
from
the
dorsal
side
of which
issue
endogenous
erect
branchlets. The
distance between these
branchlets varies somewhat in the different
specimens, but each specimen has generally about the same number
of segments between the branchlets
; for instance one specimen had
only about 4
5 naked segments between those bearing branchlets,
another specimen had
10
12 segments.
Trichoblasts
are
entirely
absent upon the creeping stem.
This grows by means
of a large
apical cell (Fig. 297) from which thin segments are cut off. The peri-
298
central
cells are
at
first formed on
the upper,
dorsal
side
of the
rhizome, somewhat
later on the lower, ventral side and the growth
is upon
the
whole
to
begin
with
most
vigorous
on
the
upper
side. By
this habit
of growth the summit
of the rhizome
is
tur-
ned downwards
towards
the
substratum
(Fig.
297),
later on by
augmented growth on the lower side this curve is again eliminated.
From the pericentral
cells
of the ventral
side
of the rhizome
hapters
grow
out,
fixing
the
plant
to
the
ground
or
to
other
algae
(Fig.
295). The
rhizoids
are
in
open
connection
with
the
mother
cell;
they
have very thick
walls,
their lumen
being
re-
duced
to
a
narrow
channel;
they
end
in
an
irregularly
lobed
disc. The rhizomes
are
about
80
120^
thick and the segments
about as long as broad
or somewhat
shorter, about 80 u
long.
Fig. 296.
Lophosiphonia
crislata Fal-
Fig.
297.
Lophosiphonia
cristata Fal-
kenberg.
Transverse
section
of
the
kenberg. Summit of creeping filament,
thallus. (About 150:1).
(About 265:1).
The erect
branchlets
are
to
begin with
not curved
in their
upper end and
are destitute
of trichoblasts (comp. Fig. 295). But
soon
the
summit
becomes
curved
or
even somewhat
involute.
The hook-formed summit
it always turned
forwards towards the
growth-point
of the rhizome.
When
the
branchlets
have
reached
a
certain
length, which
varies somewhat in
the
different branchlets, they begin to develop
triohoblasts from the convex
side
(Fig. 298). The
trichoblasts are
placed
in a
single row, at
first
at some distance from each other,
but
later
on
nearer
and
nearer
until
at
last
nearly every
seg-
ment has
a trichoblast.
The
development
of
the
trichoblasts
begins very early and
proceeds
so
vigorously
that
they
are
rather
large
even
before
the segment which bears a trichoblast
is divided
(Fig. 298).
The branchlets
have
at
their base nearly the same number
of
pericentral
cells
as
the
rhizome,
but
higher
up,
as
already
mentioned, a larger number.
I have counted
10
12. At the same
time
as the number
of the
cells increases the
cells grow shorter;
299
thus
in one branchlet the
cells had
at
its base a length
of about
70^,
while
higher up
in the branchlets they had
only
half
this
length, about
35//.
By and by
as
the branchlets
grow longer they
at the same
time become straight, the cells being lengthened in the concave side
in proportion to those of the convex side ; by this way of growing the
uppermost summit of the branchlet only is constantly hook-formed.
The trichoblasts are
unilaterally
developed
and
when
young
they
curve in the same direc-
tion
as
the
summit
of
the branchlet (Fig.
298).
Later on they are
straightened and assume
the common appearance
of the trichoblasts. They
are vigorously developed
and 45 times pseudo-
dichotomously
divided.
Nevertheless
they
are
generally
shed
early,
leaving back clearly ob-
servable scars.
It
has
been
men-
tioned
above
that
the
trichoblasts
are
seriated,
but,
as
pointed
out
by
FALKENBEBG,
a trichoblast
is
occasionally
placed
somewhat out
of the
series.
This
is according to FALKENBERG
still more the case in the tetra-
sporic plant, but having had only sterile plants
at my disposal,
I
refer as
to
this matter to the
description
of FALKENBERG.
The
plant was
found
in a rather
exposed
locality, growing
between and
sheltered by some larger algaB. These
alga3, especially
Caulerpa racemosa
f. reducta, Cladophoropsis membranacea, Valonia
utricularis, Jania
etc.
formed
upon
the
reef
a
dense
carpet
in
which
smaller
alg?e,
e.
g. Polysiphonia ferulacea and
the present
one were
creeping.
On the shores
of the islands
it has only been found once, at
St. Tho-
mas: Near Charlotte Amalia on the
reef
connecting
the Hurricane
Island
with
St. Thomas.
Geogr.
Distrib.
:
Hitherto
only
found
once
in
the
Mediterranean
Sea
at Naples.
Fig. 298. Lophosiphonia
cristata Falkenb.
Summit of branchlet. (About
180:1).
300
Subfam.
6. Bostrychieae.
Bostrychia Montague.
1.
Bostrychia tenella (Vahl)
J. Ag.
AGARDH,
J., Spec. Alg., vol. II, p.
Ill, p. 869.
Analecta Algologica, cont.
IV,
1897,
p. 83. FALKENBERG, P., Rhodomelaceen,
p. 515.
Fucus
tenellus Vahl, Endeel kryptogamiske Planter fra St. Croix (Skriv-
ter af Naturh. Selskab,
5te
Bd.,
2
Hefte, Kiobenhavn
1802,
p. 45).
For more synonyms compare: DE-TONI, Sylloge Alg., Vol. IV,
p. 1162.
Bostrychia
tenella
(Fig.
299) occurs
as
a rather common
epi-
phyte upon the roots
of the mangroves,
or
it grows upon stones
Fig. 299. Bostrychia tenella (Vahl)
J. Ag. Part of a plant. (About 8:1.)
and
rocks near or
in shaded
localities somewhat above
the
sur-
face
of the
sea.
It
has
6 to
8 pericentral
cells,
8
in
the
older main
stems,
fewer upwards
in the branches;
in the branchlets the number
of
pericentral
cells decreases more and more, making an even
transi-
tion to the often long monosiphonous summits
of
these.
The
pericentral
cells
are
in
an
early stage
of development
divided by horizontal walls into two
cells.
From the outer
sides
of these
cells, as described by FALKENBERG, cells are cut
off from
which
the
cortical
layer
originates.
This
makes
a
thick
cover
upon
the main stem
(Fig.
300),
thinner upon the side-branches,
and
disappears
gradually upwards, the thinner
branchlets
being
quite uncovered.
301
The main
filaments
increase by means
of a
large
apical
cell
from which
flat segments
are cut off (Fig. 301), Alternately, from
each
of these, branches
issue forming two opposite rows.
Fig. 300. Bostrychia tenetta(Vah\] J. Ag.
Transverse section of the thallus.
(About
150:1).
Fig. 301. Bostrychia tenella ( Vahl) J. Ag.
Top
of a filament.
(About 200:1).
My specimens
belong
to
the typical
form, having
the
side-
branches arranged distichously.
Bostrychia
tenella
is
fastened
to the substratum by means
of
vigorous
rhizoids growing out anywhere from the filaments
(Fig.
299). As
described by FALKENBERG
these haptera
consist
of con-
genital
outgrowths
from a group
of
surface
cells,
these
at
first
forming
together
a
vigorous
stem,
later becoming more
or
less
separated or broadened out to a small disc (Fig. 302).
Upon a transverse
section
of the main
stem
it
is seen
that
the
central and
pericentral
cells have
very thick and
stratified walls
(Fig. 300).
Plants with tetraspores and cystocarps are found.
The
stichidia
are
formed
in
the
ends
of
the
ramuli and have mostly four, sometimes fewer, verti-
cillated
sporangia
in each segment.
I have
not ob-
served
any tendency
to
uniseriated
stichidia.
The
sporangia
are tetrahedrically divided.
The cystocarps (Fig. 303) are placed in the sum-
mits
of the
side-branches.
Their
shape
is
spherical-
urceolate.
Bostrychia tenella was originally described by VAHL
from specimens from
St. Croix.
It occurs both
in
sheltered and in more exposed
places, and
where
it
is constantly moistened by the spray
it
is able
to grow
somewhat
above
the
surface
of
the
sea,
especially when
found
Fig. 302.
Bostn/chia
J.Ag. End of
ayounghap-
ter.
(About
125:1).
202
Fig.
303.
Bostrychia
tenella
(Vahl)
J.
Ag.
Summit
of
branch
with cystocarp.
(About
25:1).
in
its
favourite growing places: dark ravines
etc.
It has been found with tetraspores and
cystocarps
in the month
of January.
St. Croix: The harbour of Christiansted and
the lagoon
at
the
same town;
Salt River Lagoon.
St. Tomas:
St. Nordsidebugt.
St. Jan: Cruz Bay.
Geogr.
Distrib.
:
Widely
distributed
in
all
warmer seas.
Subfam.
7. Lophothalieae.
Lophocladia Schmitz.
1.
Lophocladia trichoclados
(Mert., C. Ag.) Schmitz.
FR. SCHMITZ, Die Gattung Lophothalia
(Ber. d.
deutsch.
bot.
Ges.,
Bd. XI,
1893,
p.
222). FALKEN-
BERG,
P., Rhodomelaceen,
p. 553.
Conferva trichoclados Mert. mscr.
Griffiihsia trichoclados Ag., Spec. Alg.,
II, 1828,
p.
132.
Dasya lophoclados Mont, in Ann. Sc
Nat., Bot.,
II.
ser.,
1842,
p. 254; HARVEY. Nereis Bor.-Am.,
II,
p.
65.
Polysiphonia
lophoclados
Kiitz..
Spec.
Alg.,
p.
834; Tabula? Phycol. XIV,
tab. 22,
fig. a
b.
Dasya trichoclados
J.
Ag.,
In Historian!
Alga-
rum Symbolse,
LinnaBa, vol.
15,
1841,
p. 32; Spec. Alg., vol.
II,
p.
3,
p. 1229.
Lophothalia (Lophocladia) trichoclados J. Ag.,
Till. Algernes Systematik,
XI,
Florideae,
p. 64.
The
figure
(Fig. 304) shows the summit of a
filament. From
the large
apical cell disc-formed segments are cut
off. From these
the trichoblasts soon grow
out, before they
are yet divided, the
segments being divided rather
late
into a central
and
four pericentral
cells. Also in the trichoblasts
transverse walls
are developed rather
late.
The trichoblasts
are placed in a screw turning
to
the
left
with
a
divergency
of
*/4,
one
from
each segment
(Fig. 305). They are monosiphonous
throughout
their whole
length
and
several
times
branched.
As
is
usually
the
case
the
ramifica-
Fig. 304. Lopho-
cladia
trichocla-
dos
(Mert..
C.
tion
in
the
lull
grown
tnchoblast
seems
to
be
Ag.)
Schmitz.
dichotomous but when young stades are examined
we
see
that
it
is
monopodial
with
alternate
Summit of a fil-
ament.
(About
260:1).
203
branching
(Fig.
306).
In
the
fully
developed
trichoblast
all
the branches are arranged
fan-
like in one plane, the trichoblast
turning
its
flat
side against the
main
filament
(Fig.
305).
The
basal
cell
of
the
trichoblasts
bears
no
side-branch,
is
very
short
and
more
or
less
sunk
between
the
pericentral
cells;
then follows a short
cell bearing
the
first
side-branch. This is al-
ways
found
at
the
right, ano-
dic,
side
of
the
trichoblast.
It
begins with a
short, basal
cell.
In
the
next
branch
the
basal
Fig.
305.
Lophocladia
trichoclados
(Mert., C. Ag.) Schmitz. Part of a fila-
ment with trichoblasts. (About 45: 1).
cell
is
still
short, though somewhat
longer. The
first side-branch
of the trichoblast
is that which
is trans-
formed
into the stichidium (comp. Figs.
306 and
307).
In the
fully developed trichoblasts
the cells are long and cylindrical, about
23 p
thick and
250 a
long,
somewhat
shorter and thicker towards the bottom,
longer and thinner towards the top.
Exogenous branches formed
in the
summit of the plant seem to be entirely
wanting.
I
have
looked
for
them
in
vain,
and
FALKENBERG
did
not
find
them
either.
The
ramification
of
the
plant takes
place by means
of endoge-
nous,
adventitious branches, formed la-
ter. The segments in the main filaments
are
about 175
ij.
broad, being
scarcely
double
this
length, about 270
long.
In
the
upper young
parts
of
the
filaments no
cortical
layer
is
present;
the
older parts
of the filaments on the
other hand are more or less covered by
cortex. The
first beginning of the cort-
ical layer
is formed by rhizoids growing
Fig. 306. Lophocladia tricho-
clados (Mert., C. Ag.) Schmitz.
Young trichoblasts near the
summit of a filament, show-
ing development of stichidia.
The uppermost one
is
still
undivided, the following con-
sists of four cells, the lower-
most of five. (About 260: 1\
304
out
from
the
basal
end
of
the
pericentral
cells
(comp.
Fig.
307)
and
running
down
in
the
furrow
between
these
cells
(Fig. 305).
Most
of my
specimens were
richly
provided
with
stichidia
(Fig. 307). As the
figure 306 shows, these
originate from the
first
side branch of the
trichoblast which
issues from the second joint
in these. One or two segments in the basal part
of the stichidia
remain undivided.
All the following
segments become polysipho-
nous
with
the
exception
of some
of the uppermost
ones, which are
small,
ste-
rile
and
not
divided.
As
described by SCHMITZ
(1. c.,
p.
233)
the
stichidia
are
unbranched,
but
this
is
only apparently
so,
accor-
ding
to
Falkenberg's
ob-
servations.
For, as pointed
out by this author, a small
cell
is
cut
off
from
each
segment
by
an
oblique
wall, these small
cells
pla-
ced with a divergency of
1U
round
the
stichidia, being
the first beginning of bran-
ching. Normally these cells
Fig.
307.
Lophocladia
trichoclados
(Mert.,
e
i
i
C. Ag.) Schmitz.
Part
of
a
filament with
are not further developed,
the lower parts
of two trichoblasts and a
and
I have not
succeeded
stichidium. Some of the tetrasporangia have
~
..
>-,
fallen
out.
The
downwards directed out-
m
finding
any
stichidia
growths from the two pericentral cells are
with
branches,
but
FAL-
the
beginmn^g
cortical
layer.
KENBERG happened to find
one in which the cells in the
monosiphonous branches reached the number of 13. The first pericen-
tral
cell in the segment
is formed
under this small
cell, and be-
comes
therefore
shorter than
the
others,
of which one
is
fertile.
A
single
tetrasporangium
is
shaped
in
each
segment; they
are
placed
in screw line and the stichidia upon the whole are beauti-
fully
screw-formed
(Fig. 307). The
tetrasporangia
are tetrahedri-
callv divided.
305
As
far as
I know the tetrasporangia
are up to this date the
only known organs of
fructification of
this
plant. The discovering
of a small
piece
of a male plant and of a female one, was there-
fore
of much
interest.
Neither the antheridia nor the cystocarps
show any more
essential
peculiarities;
both kinds
of fructiferous
organs
are very
like those,
e. g. found
in Polysiphonia.
As, in the case
of the stichidia, the antheridial stands (Fig. 308)
are found
in the tricho-
blasts and originate from
the
first
side-branch
of
these.But whilethe whole
side-branch is employed
in
the
development
of
the stiehidium,
this nor-
mally having no branch-
lets,
this side-branch
in
the male plant has one
to three
branchlets
be-
sides the terminally pla-
ced
antheridial
stand.
The
antheridial
stands
are
cylindrical
to
spindle-shaped, with an
obtuse
apex.
At
their
base they have
a stalk
composed
mostly
of
three
short
cells and, at
their summit, two small
Sterile cells.
Fig. 30<s. Lophocladia trichoclados (Mert., C. Ag.).
The development of
Schmitz. Part of
a filament with
trichoblasts,
two
of which bearing antheridial
stands,
the
antheridial
stands
(About 100
: 1).
takes place in the follow-
ing
manner:
the
branch
at
first
is
divided
by
transverse
walls
in a number of
short
cells above
each .other
(Fig. 309 a)
where-
upon these
again are divided:
firstly by longitudinal
walls
(Fig.
309 6),
later by walls
in various directions into a great number of
small roundish-polygonal
cells
at the pheriphery. From these the
antheridia
are formed.
The procarps originate from the second segment of the tricho-
blast
(Fig. 310).
This
becomes
polysiphonous,
consisting
of
the
central
cell and the five pericentral ones
as always
in the case of
20
306
the RhodomelaceaR even if the vegetative segments have another num-
ber. The basal segment of the trichoblast does not become polysipho-
Fig. 310. Lophodadia trichodados
(Mert., C. Ag.)
Schmitz.
The
basal
part
of
two
trichoblasts
with procarps.
(About
265:1).
Fig.
3U9. Lophocladia
tri-
i-liochidns
(Alert.,
G.
Ag.)
Schmitz.
Two young an-
theridial
stands
in
vari-
ous stages of de\
7elopment.
(About
265:1).
nous until the procarp
is more developed
(cfr.
Fig.
310).
The
upper
sterile part
of the
tri-
choblast
remains
mo-
nosiphonous and undi-
vided..
The
figure
310
shows
the
only
two
stages
of development
found,
but
to
judge
from
these
the
cysto-
carps are developed in
the
usual way
found
in
the
Rhodomelacese .
One
of the
pericentral
cells
is divided by a longitudinal wall into
two
cells:
one
of these being the
auxiliary mother cell, the
other
one producing
the
carpogonial
branch.
The trichogyne
is
rather
Fig.
311. Lophocladia
trichodados
(Mert.,
C. Ag.'l
Schmitz.
A
ripe cystooarp.
(About
60:1).
307
short,
clavate
and
of the same shape
as the one
often found
in
the Rhodomelaceas.
I have not been
able to follow the further development. The
mature cystocarp
(cp. Fig. 311, the only one
found)
is lageniform
having a rather long neck and a roundish basal
part.
Lophodadia
is
fixed
to the substratum
(stones,
shells
etc.
or
other
algse) by means
of vigorous
rhizoids breaking out from the
decumbent parts of the filaments (Fig. 312). These rhizoids are mono-
siphonous or plurisiphonous. They end in a disc. From the creeping
Fig.
312. Lophodadia
irichoclados
(Mert., C.Ag.) Schmitz.
Basal, decumbent part
of filaments with rhizoids and
larger haptera.
(About
80:1).
decumbent parts of the filaments the free upper ends bend upwards
(comp. Fig. 312) or new erect branches are produced.
Regarding the
hyphse-like
rhizoids,
mentioned
above,
which
form the
cortical
layer, we
find that these
at their outgrowth are
separated from the mother pericentral
cell by a wall. By a mistake
this wall has been omitted in
Fig.
307.
This
plant
has
apparently given FALKENBERG much trouble
with regard to the trichoblast and the occurrence of the stichidium
upon
it. While FALKENBERG begins his description of this plant by
calling the trichoblasts"Kurztrieben"(l.c., p. 553) he ends by saying:
"Meiner Ansicht nach liegt die Sache nun so, dass wir bei Lophodadia
trichodados echte Blatter haben". And, as to the formation
of the
'20*
308
stichidium
in
the
trichoblast,
he
thinks we have to do with an
axillary
branch.
As
his
interpretation
seems
to me somewhat
difficult
to understand and
-
- furthermore, as my observations do
not
always
agree
with
his,
I
shall
here
enter a
little more
into
this
question.
SCHMITZ, the founder of the genus Lophocladia, considered the
stichidium to be a transformed part of the trichoblast or "Haarblatt"
as
he
calls
it.
FALKENBERG,
on
the
other
hand,
objects
to
this explanation. The fact that the distichously ramified and mono-
siphonous trichoblast
in the stichidial part becomes plurisiphonous
and spirally ramified leads him to the following conclusion: "Ich bin
geneigt in dem Stichidium, gerade so wie bei Lophothalia und Doxo-
dasya, einen durch sein Fertilwerden wenig modificierten Langspross
zu erblicken,
der an der Basis
des
Kurztriebs gewissermaassen
als
Achselspross
aufgetreten
ist". As my figure
(Fig.
307) shows, the
stichidia are never placed at the base of the trichoblasts, but upon
the second basal cell of these, and how the stichidia in this case can
be explained as axillary branches
is
difficult to understand.
In the following FALKENBERG
tries to
particularize
his
inter-
pretation; but as
I
differ from his opinion on several points
I think
I had better quote the paragraph in
extenso.
FALKENBERG
says:
"Und
gewichtige
Gri'mde
lassen
sich
fur
diese Annahme
anfiihren, wenn
es mir auch
nicht
gelungen
ist,
durch
Beobachtung
der
Entwicklung den
direkten
Beweis
dafur
zu
erbringen;
bei der ausserordentlichen
Kleinheit und
der
dicht-
gedrangten Stellung
der Kurztriebe am Vegetationspunkt habe ich
nicht nachweisen konnen, ob die Stichidien, wie das ja nothig ware,
thatsachlich
als
eine secundare Bildung nachtraglich am Kurz-
trieb sichtbar werden. Aber die Stichidien treten an solchen Segmen-
ten der monosiphonen
Kurztriebe
auf,
die
-
wenn letztere
steril
bleiben
iiberhaupt
keine
seitlichen
Glieder
produciren.
Daraus geht eigentlich schon hervor, dass das Stichidium nicht aus
der Metamorphose
eines auch am
sterilen
Kurztrieb vorhandenen
Seitengliedes entstanden ist
-
- sondern dass es als ein Novum, und
z\var nur an den fertilen Kurztrieben auftritt."
Regarding the first sentence
I need only refer to my figure (Fig.
306) showing the
development
of
the
stichidia.
In
the most
ob-
vious manner
it
reveals
the
stichidium
as
the
first
side-branch
upon the main filament of the ramulus. FALKENBERG'S supposition
809
that the stichidium should be
"sichtbar nachtraglich am
Kiirz-
trieb" does not agree with my observations.
Nor is his next sentence corroborated upon examination of the
plant. FALKENBEKG maintains here that the stichidia originate from
segments of the trichoblasts which, when the trichoblasts are sterile,
are never provided with branches. As is seen from figs. 305 and 307
a side-branch is always developed from the second segment
in the
sterile trichoblast, that is to say, just in the same place as that occu-
pied by the
stichidium in the
fertile. According to my view and in
contradiction
to
that
of
FALKENBERG, we
arrive
at the
follow-
ing conclusion:
that the stichidium has come
into
existence
just
through the metamorphosis of the
first side-branch issued from the
trichoblast and,
it cannot
therefore
be considered
as
a
"novurn"
found only upon the
fertile trichoblast.
And the occurrence
of the antheridial stands just in the same
side-branch
of the trichoblast as the
stichidia
(a part of this
side-
branch
being
polysiphonous
and
transformed
in
the
antheridial
stand just as in the case of e. g. Polysiphonia), seems to me still more
to corroborate the correctness
of my view.
As to the rest of FALKENBERG'S reflections concerning this sub-
ject
I am not going to discuss them here. For we have solved the
difficulties when we
look upon
the ramulus
as
a
trichoblast
( =
Haartrieb OLTMANNS).
Concerning
the
trichoblast and
its relation
to the stem
I just w
rant to refer to ROSENVINGE'S instructive paper
:
"Sur
les
organes
piliforme
des
Rhodomelacees" *) and
especially
to chapter 5: Formes intermediates entre tiges et trichoblastes" and
to OLTMANNS remarks in Morphologie und Biologie der Algen, Bd. 1,
1904,
p. 609 and
especially
p. 709.
Besides some
specimens washed
ashore
I
have only
dredged
this plant in deep water at about 10
15 fathoms in rather open sea
and in places where strong currents prevailed.
It was found with
tetrasporangia in the months January
March and with antheridia
and cystocarps in the month
of March.
As in the case of so many West Indian algae this one, too, seems
originally to have been described from specimens gathered at the
*)
In Oversigt
over
det
kgl.
danske
Videnskabern.es
Selskabs
Forhand-
linger,
1903, Xo.
4.
310
Danish islands; comp. J. AGARDH, Spec. Alg., vol.
II, p. Ill, p. 1230.
Later on 0RSTED
collected
it at
St. Thomas and
St.
Croix.
St. Croix: Near Green Cay Estate and at the entrance
to the lagoon
of Christiansted
(both
places washed
ashore).
St. Jan: Dredged
in many
places
in the sound between
this island and
St. Thomas.
Geogr. Distrib.: West
Indies.
Wrightiella
Schmitz.
1.
Wrightiella Tumanowiczii
(Gatty) Schmitz.
SCHMITZ,
FR.,
Die Gattung Lophothalia
J. Ag.
(Ber. der deutsch.
bot.
Ges., Bd.
XI,
1893,
p.
222.
FALKENBERG,
P., Rhodomelaceen,
p.
559.
Dasya Tuntanoiciczii
Gatty
in HARVEY.
Nereis Bor.-Am.,
part
II,
p.
64.
Ki'TziNG, Tabul.
Phycol.,
vol. XIV,
tab.
63.
The plant has four pericentral
cells which on a later stage are
more or less covered by a cortical layer (Fig.
314).
What
especially distinguishes this plant
are the
polysiphonous, short, spinelike endogenous branchlets
found
scattered
upon
the
thallus.
Moreover
it
is
endowed with exogenous, mostly short
living, mono-
siphonous
side-organs. These FALKENBERG
refers
to
as ''monosiphone
Kurztriebe
(nicht
Blatter)",
I
call
them trichoblasts.
The
plant
increases by means
of an
apical
cell
from which flat segments are cut off (Fig. 313); from
these the trichoblasts begin to grow out long before
Fig. 313.
j-
-j
\\-rightiellaTu-
the segments
are
divided.
nmnowiczii
The trichoblasts
are placed in a screw
line, with
Schmitz
a divergency
of %
f the periphery, upon
the main
Summit of the
filament
(Fig. 314) and
consist
of
a monosiphonous
500-1)
mam stem, from which the monosiphonous branches
issue
spirally
with
a
divergency
of
1
/s
1
/4.
In
the
sterile
plant
the
cells
in
the
trichoblasts
are
small
at
the
base,
increasing
evenly
until
somewhat
above
the
middle
of
the
whole
trichoblast,
then
tapering
slowly
to
the
blunt
or
generally
acute
ends
of
the
filaments
(Fig.
315).
The
cells
of
the trichoblast are
cylindrical
or barrelshaped with thin walls.
In the trichoblast both the tetrasporangia and the cystocarps
are developed. When we have to do with the last mentioned organs,
\\hirh
I have not found in my specimens, the trichoblasts, according
to FALKENBERG,
are more
persistent and the lowest segments be-
311
come polysiphonous
(cfr. FALKENBERG,
pi.
13,
fig.
14). In the tetra-
sporic plant, on the other hand, the upper end of the main stem in
the trichoblast becomes polysiphonous and transformed into
stichi-
dia, while the lowest part remains monosiphonous
(Fig.
317 a).
The polysiphonous side-or-
gans are developed quite
inde-
pendently of the trichoblasts. As
pointed
out
by
FALKENBERG
they
are
of
later
origin than
the trichoblast,
first
appearing
after
the
division
of the
seg-
ments
in
the
main
filament
and must be considered as ad-
ventitious
branches.
FALKEN-
BERG found them rather regu-
larly
distributed
,
generally
placed
with
14
divergency
a
single one upon each segment.
In my plants the arrangement
was not so regular, as segments
without branches
often
occur-
red. As indicated by FALKEN-
BERG the central axis
of these
reaches into the central
cell in
the main
filament
(Fig.
316);
this,
I
think,
largely supports
the supposition that they really
are
of endogenous
origin. The
greatest part of these branches
remains short
, and spinelike ; now
and then
a
single one
gets
a
continuous growth like the main
filament and contributes to the
ramification
of the
plant. The spinelike branchlets are
of a rather
soft
consistence
;
they
are always
undivided and
consist of up to
ten segments with four pericentral cells, the segments getting smaller
and smaller towards the top. In the uppermost segment only a single
cell
is
present.
From the basal pericentral
cell
of these branchlets hyphse-like
Fig.
314.
Wrightiella
Tumanowiczii
(Gatty) Schmitz. Part
of a main
axis
with trichoblasts and spinelike branch-
lets. From the basal cells of these hy-
phse
are seen growing downwards
for-
ming the
cortical
layer.
'
< About
6(1:1).
312
filaments grow downwards
in
the furrow between the pericentral
cells of the main filament (Fig. 314)
; later on from the other basal
pericentral cells in the branchlets similar filaments are issued, form-
ing together the
cortical layer surrounding the
central axis in the
main filament.
As already mentioned the
stichidia
(Fig.
317)
are formed
in
the upper
end
of the
trichoblasts. The upper end
of the
central
axis
becomes
polysiphonous
and a sporangium
is developed
in each segment. The sporangia
are
arranged
in
a
spiral
line
and,
as
they
increase
in
size
proportionately
much
more
than
the
sterile
cells
of
the
I
\
Fig.
315.
Wrightiella Tumanowiczii
(Gatty) Schmitz.
Part
of young
fila-
ment
with
trichoblast
and
spinelike
branchlets.
(About
90:1).
Fig. 316. Whrightiella Tumanowiczii
(Gatty) Schmitz. Tranverse section
of a niain stem from the place where
a
spinelike branchlet
is issued.
(About
50:1).
segments,
the whole
stichidium becomes
screwformed. As
in the
case
of
the
sterile
part
so
also
in the
fertile
one
each
segment
carries a monosiphonous ramulus. In the fertile part these are often
rather short. A short, sterile tip with small ramuli arranged spirally
rvowns the
stichidia.
The fig. 317 shows a comparatively short stichidium and a longer
one; these contain often twenty or even more sporangia. The basal
monosiphonous part of the trichoblasts
is in
all essentials like that
of the sterile trichoblasts; but the cells are slender and, on the other
.313
hand, longer, nearly cylindrical
of shape:
it
is generally rather long,
I have counted 22 joints in the main
axis.
In
their outward appearance the specimens found do not to
any great extent resemble either Wrigktiella Blodgettii or W. Tuma-
nowiczii. They are very
irregularly
ramified,
and
the
trichoblasts
are very perishable and
only to be found in the
uppermost ends
of the
branches. The spinelike
branchlets are short and
scarcely visible. On ac-
count
of
this
fact
I
have referred my plants
to Wrightiella Tumano-
wiczii.
But, as pointed
out by
Si HMITZ
(1. c.,
p.
222) who examined
original
specimens
of
both
species, they
are
very
nearly
related
and FALKENBEKG even
points
out
that most
probably the two plants
are
nothing
else
but
different forms
of
the
same species. The fact
that my
plant
differs
in appearance from the
others may perhaps be
due to its occurrence in
deep water, suggesting
at the same time that
most probably the plant
is rather a plastic one.
This plant was dredged in about
10
15 fathoms of water in
rather open
sea.
It had tetrasporangia
in
the month
of March.
St. Jan:
Off Cruz Bay in the sound between this island and St. Thom;r-.
Geogr. Distrib.:
Florida (Key WesO, Bermuda.
Fig. 317. Wrightiella Tumanowiczii(Gaiiy) Schnvtz.
a,
part
of main
stem
with
spinelike
branchlet
and a trichoblast with stichidium.
b, a stichidium.
(a, about
60:1;
b, about
100:1).
314
Murrayella Schmitz.
1.
Murrayella
periclados
(Ag.) Schmitz.
SCHMITZ.
FR., Die Gattung Lophothalia
J. Ag. in Berichte
d.
deutsoh.
bot.
Ges., Bd.
XI,
1893,
p.
227.
FALKENBERG,
P.,
Rhodomelaceen,
p.
563,
pi.
12,
figs. 2425.
Hutchinsia periclados Ag.,
Spec.
Alg.,
vol.
II,
p.
101.
Polysiphonia periclados
Kiitz.,
Species Alg.,
p.
822.
Bostrychia Tuomeyi Harv., Nereis
Bor. Am., Part II, p. 58, pi. XIV E.
Bostrychia periclados
J.
Ag.,
Spec.
Alg.,
vol.
II,
pars
III,
p.
861.
Polysiphonia Binderi Sender
in
Kiitzing, Tab.
Phycologicse,
vol. XIV,
pi.
45
a,
b.
Murrayella periclados is a common mangrove alga forming upon
the roots of the mangroves dark red -brown, densely felted cushions.
These consist of basal creeping filaments from which the erect ones
grow up (Fig 318).
The creeping filaments can be more or less destitute of branches,
but in most cases these are to be found even
if they often are rather
scarce and for the most part not much developed.
The
creeping filaments
are
fastened
to
the sub-
stratum by means of rhizoids (Figs. 318 and 319).
The
rhizoids grow out
near the ends
of the
pericentral cells. They issue singly or often several
together from the same segment (Fig. 319).
In this
case
the
rhizoids
are
mostly
grown
together
at
their base, forming a bundle. Higher up the rhizoids
become gradually free, spreading in
all directions.
These rhizoids remind one much
of those found in
Bostrychia. The rhizoids
are
often branched
; they
have
cross walls and rather long cylindrical
cells,
about 3
5 times as long as broad
; they
are rather thick-walled, with stratified
walls,
often
penetrating
a
little
into
the bark of the mangrove,
the
cells of
which
fre-
quently
are
attached
to
the
rhizoids
after prepara-
Fig.
318.
Miirrni/rllii
perir-ldilos
(Ag.
i
tlOll
Srliniitz,.
Part
of
a
plant.
(Fiff
318)
(About
8:1).
315
The plant has four pericentral cells
and
altogether
lacks
a
cortical
layer.
It increases by means
of an apical
cell
from which
flat
disc-formed
segments
are cut
off. From these the side-organs
issue
spirally with a % divergence be-
fore the segments are divided.
As described by FALKENBERG
the
side-organs are of three
different types.
The most common are the unbranched,
monosiphonous
ones
(Fig.
318);
these
occur especially in the basal part of the
main filaments and on the whole in the less
vigorous filaments. The cells in these are
about 28
(LI thick and 60
u. long.
The second type
consists
of
disti-
chously ramified branchlets
(Fig.
320).
Kiii'. 319.
Murrayclla periclados
(Ag.)
Schmitz.
Part
of
cree-
ping filament with rhizoids ;ind
erect branches.
(About
35:1).
The main axis in these branchlets
is polysiphonous, while the side-
organs are monosiphonous and these occur alternately
on both sides
of
it.
Between these two
kinds
of branchlets an even
transition
is to be found. As pointed out by FALKEN-
BERG it may happen that the monosiphonous,
not ramified branchlets have a plurisiphonous
base and, on the other hand ramified
branchlets occur which are
monosi-
phonous throughout and further, re-
garding the ram ification of the branch-
lets, an even trans-
ition
is
also
pre-
sent
here
as
bran-
chlets with
a single
side-branch
are
found,
others
with
two or more.
Finally the
third
Fig.
320. Murrayella periclados
(Ag.) Schmitz.
Part
kind
of side-organs
af a plant with stichidium having several well-deve-
C0nsists of branches
loped ramuli.
(About
50:1).
with
polysiphonous
316
main
axis and screw-formed
side-organs. These branches grow out
to ordinary branches and contribute to the ramificatoin of the plant.
The stichidia are found in the ends of the distichously ramified
branchlets (Fig. 320). The lowest parts of these branchlets are provided
with side-branches as in the case
of the
sterile ones.
In the
fertile
part, on the other hand, the
side branches
are normally
missing.
Each of the four pericentral cells in each segment produces a tetra-
sporangium, and
is covered with three
cells. The tetrasporangia are
about 55
LI broad, the whole stichidium about 105 u thick; in the
upper end of the stichidium a short vegetative prolongation is often
developed
; this consists of several small segments from which short
side-branches issue spirally.
When
I wrote above that
the stichidia are normally destitute
of side-branches,
I ought, however, to have pointed out that
I have
found a few stichidia with well developed monosiphonous, unbranched
ramuli placed in a screw (comp. Fig. 320 in which some ramuli are
developed
in
the
low
rer
part
of the
stichidium).
I
mention
this
especially
as FALKENBERG always found the stichidia without side-
branches and maintained that just this absence of the side-branches
makes Mnrrayella only slightly related to the
typical Lophothalieds.
Murrayella peridados was found with tetraspores in the month
of January. It occurs in nearly all lagoons and bays where mangroves
thrive and
it grows near the surface
of the
sea or a
little above.
This
plant was
described
originally from specimens from
St.
Croix which HOFMAN BANG presented to C. AGARDH
St. Croix:
Christianssted's
Lagoon,
Salt River.
St. Thomas; Bo-
voni Lagoon.
St. Jan: Cruz Bay.
C-eogr.
L) 1st rib.: West
Indies.
Florida, La Guayra.
Subfam.
8.
Dasyeae.
Dasya
C.
Ag.
1. Dasya
pedicellata Ag.
\',UU>H,
C., Systema
Alg., 1824,
p. 211. COLLINS, F., and A. HERVEY,
Algae
of Bermuda,
p.
136.
Dasya elegans
(Mart.)
Ag.,
Spec.
Alg.,
vol.
II,
1828,
]>.
117.
KLTZING,
Phyc.
gener.,
p.
414.
pi.
51,
fig.
II,
Spec.
Alg.,
p. 796. Tab. Phycolog.,
vol.
XIV,
tab.
59. HARVEY.
Nereis
Bor.-Am., part
II,
p.
60. FALKENBERG,
P.,
Rhodomelaceen,
p.
618,
pi.
18,
figs.
5
17.
317
Rhodonema elegans Martens,
Reise,
II,
p.
641,
tab.
VIII.
Dasya Kiitzingiana Biasoletto
in Linnaea. vol. XI,
1837,
p. 477, pi. VIII
and IX. KUTZING, Phycol. gen.,
p.
414,
pi. 51, II,
figs. 1
4; Tab. Phycolog.,
vol. XIV,
pi.
60.
For more synonyms
see DE-TONI, Sylloge Algarum,
vol. IV, part
III,
p.
1201.
This
fine plant is found at the islands in deeper water, about
20
40 meters, and seems at this depth to be common.
Referring
for
details
to FALKENBERG'S exhaustive
description
I just want to mention here that the summits of each branch-system
of the sympodium (the ramuli as
I call them) are placed with a diver-
gency of about V. Later on from the surface cells of the very early
developed cortical layer numerous adventitious branchlets
are
de-
veloped
; these are placed quite irregularly and often cover the main
filaments very
densely.
The stichidia are developed
at the summit of the unbranched
filaments of the ramuli. The stichidia are linear-lanceolate running
out in an
acute
sterile
apex;
five
sporangia
are present in each
joint.
The
cystocarps
are
developed upon
the
ramuli whose
basal
parts then becomes
polysiphonous. They
are
urceolate
of
shape,
often somewhat oblique with a rather long and narrow neck.
Dasya pedicellata has been found in more open sea and rather
deep water mostly in places where rather strong currents
prevail.
Specimens with tetraspores and cystocarps were found in the month
of March.
Found
in many
places
in
the
sound
between
St. Thomas and St.
Jan,
and
in
the
sea
to
the
north
of the
last mentioned island:
off Ame-
rica
Hill.
Geogr. Distrib.: West
Indies, the warmer Atlantic shores
of North
America and Europe, Mediterranean
Sea.
2. Dasya
mollis Harv.
HARVEY, W.
H., Nereis Bor. Am.,
Part
II,
p.
62.
J. AGARDH,
Spiv.
Alg.,
vol.
II, pars
3,
p. 1216;
Till Algernes Systematik, XI
Florideae,
p. 104.
KUTZING,
F., Tab.
Phycol.,
vol. XV,
pi.
1.
A few, not very w
rell developed specimens (No. 2131) have been
found.
Characteristic
of
this
species
is the
rather quick tapering
of the ramuli from a very robust base.
In the present form
(Fig.
321 a) the bases of the ramuli were about 50
|u thick. In some of the
ramuli a short basal cell, nearly quadratic, was found, in others the
basal cell was rather long, reaching a length of about 110
\i.
In the
318
upper ends of the ramuli the diameter of the filaments decreases to
about 7
jti, the length of the cells being about ten times the breadth.
The
stichidia have
a
shorter
or
longer
stalk and
are
placed
either near the base or somewhat higher up in the ramuli. They are
about
1B5
u broad.
\Yhile the pericentral cells of this form were rather clearly visible
in transverse sections
it was not so in the case of some other speci-
mens (my
collect no.
2090).
I want to mention these specimens in
this
place,
because, regarding their outer appearance, they bear a
a
Fig.
321.
Dasya
tnollis
Harv.
a,
part
of
a branch with
base
of a ramulus
(no. 2131).
b, tranverse
section
of the
thallus and
c, part
of
a branch with base
of a ramulus
(no.
2090).
(a, about 80:1,
b,
60:1.
c,
150:1).
close resemblance to the above mentioned form. A transverse section
of a branch
of this plant
(Fig. 321 b ) shows a tissue
of
cells larger
in the middle,
smaller outwards, the
central and
pericentral
cells
not being visible; even in young branches these
cells are not pro-
minent. The specimens
differ, too, with regard to the size and con-
struction of the ramuli (Fig. 321 c) from the above mentioned form.
At their base the cells are about 30
ja thick only, and short,
too, not
much longer than broad, growing gradually longer higher up in the
ramuli. The stichidia are placed near the base of the ramuli with a
single short basal cell only. This plant does most probably represent
another
species,
but having had so very
little material
of related
species or none at all at my disposal,
I have not been able to make
any comparison and so
I prefer to leave
it be unnamed.
Both forms were
dredged
in
deep
water
(about
30
meters)
and
both
were found
at:
St.
Jan:
off
Cruz Bay.
Geogr. D 1st rib.
Dasya
mollis
occurs
at the warmer parts of
the American Atlantic
coast.
3. Dasya
caraibica
nov. spec.*)
Frons ca. 20 cm
alta, rosea-coccinea,
teretiuscula,
filifor-
mis, quoquoversum
ramosa,
articulata.
polysiphonia, singu-
lis articulis e cellulis
pericentralibus
qui-
nis
circa
cellulam
centralem
positis
formatis, cellulis ca.
400500
jii
longis.
In
adultiori
parte
plantarum irons cor-
ticata, supra ramu-
Fig. 322.
Dasya caraibica nov. spec.
Part
of the
thallus.
(About natural
size).
losa, ramulis in superiori parte ramorum aggregatis ocellatisque, infra
nuda-
Ramuli
monosiphonii,
identidem
pseudodichotomi, ca. 4 mm
*)
I
have
had
some
doubts
whether
this
plant most rightly was
refer-
able
to Dasya ramosissima as a variety only
or
to be considered
as a
proper species, having had no authentic material
of related
species
to
compare with.
I am much obliged to Mr. FRANK S. COLLINS for having
compared one of my plants with specimens in his herbarium and for having
written
to me
that he
could not identify
it with anything he knows.
Mr. COLLINS
has
also sent my specimen
to
Dr. HOWE who expressed
his view
in
a similar way.
320
longi, in parte basali ca. 24
(a crassi ad apicem filorum versus gradatim
longiores,
apice rotundato,
ca.
8
ia
lato.
A rather large and elegant plant of dark rosy-purple colour when
dry and reaching a heigth of up to 20 cm. The specimens are much
branched on
all sides forming dense tufts;
the
branchlets become
shorter towards the summit giving the plants a pyramidal outline.
The
upper
parts
of
the
branches
and
branchlets
are
covered by ramuli.
These
are
especially densely placed at the
ends
of
the branchlets
giving
them
an
ocellate
appearance.
The basal part of the branchlets
and
branches
are
bare.
The
principal branches
are about
1
mm thick, while the branchlets
are
only about
100
[i thick.
The cortical layer
is incom-
pletely
developed
upon
the
younger branches and branch-
lets
being
here
limited
to
a
single or a few hyphse
running
down
in
the furrows
between
the
pericentral
cells
; upon the
thicker main
filaments, on the
other hand, a coherent cortical
layer
is found.
The plant has five pericentral
cells surrounding a rather large central cell. The pericentral cells reach
a length of about 300
400
JLI in the younger parts of the branchlets.
The ramuli are placed with a divergency of about
l i
; they are slen-
der and long, often reaching a length of 4mm. At their base they have
a large subquadratic
cell, about 50
(J. broad and 60
70 (along, partly
immersed in the main stem (Fig. 323 a). The cells in the ramuli are shor-
ter and thicker at their base, longer and thinner upwards. In specimens
of my collection no. 1842, upon which
I especially have based my exa-
mination, the ramuli were about 24
ja broad in the basal part and their
filaments had nearly the same breadth somewhat higher up, but then
Fig. 323.
Dasya caraibica nov. spec,
o, part
of the
thallus, with two young
plants of Aci'ochsetium opetigenum B0rgs.
b, summit
of a plant.
(o, about 60:
1.
&, about 260
:
1).
321
the filaments taper evenly upwards their ultimate summits reaching
only a ,breadth of 8
(a. The cells are often more than 200
|u long. The
summits
of the
filaments
are
obtuse.
The
ramuli
are
repeatedly
pseudodichotomously ramified; the monosiphonous branches
issue
with acute
angles. The whole ramuli are upwards directed and at
the summit
of
the
branches and
branchlets somewhat
incurved.
The specimens examined were
all
sterile.
The
Acrochasti-
um opetigenum,
oc-
curring upon Dasya
elegans and describ-
ed
on
p. 38
of
the
present volume, was
very common,
too,
on this species (vide
Fig. 323 a, two young
specimens are seen).
This
plants
re-
minds one as to
its
whole
appearance
and ramification ra-
ther much of Dasya
ramosissima, but
it
Fig. 324.
Dasya
spec,
a, part
of the
thallus with
a
ramulus.
b, base of a ramulus more magnified (nearly
the same enlargement
as that
of
Fig.
323 a).
(a, about
30:1,
b,
65:1).
differs greatly from this
species by
its much
longer ana
slender
ramuli with longer
cells and
obtuse summits.
The
large
basal
cell
is not
so markedly develo ;$
n Dasya
ramosissima, and the cortical layer is less and differently, too, devel-
oped
in
this
species.
Also the rosy-red colour
of our plant
differs
from the more brownish
of Dasya ramosissima.
Also with Dasya Harvey i our plant may be compared
; but this
has,
according to FALKENBERG,
p.
625,
four
pericentral
cells,
its
ramuli are slender and are not ocellate at the summits of the branches.
I want yet to mention a form here (my coll. no. 1790) of which
only a single plant was found.
This had nearly the same rosy-red
colour and whole habitus as the above-mentioned form with excep-
tion of the ramuli which were much more robust (Fig. 324): at their
base the
cells were 31
|u thick, somewhat higher up their diameter
increased to about 60
ja, the following
cells tapering gradually up-
21
322
\vards to 11
27
|a in the various filaments. The basal cell in the ra-
inuli was not
so marked and
proportionally smaller than
in
the
first-mentioned
form. The
ramuli were much
incurved
especially
in the upper end
of the branches.
This plant has given me much trouble.
I suppose, having not seen
any typical specimen af HARVEY'S plant, that
it comes rather near
to Dasya ramosissima, but it differs from this by its rosy-red colour
and different habitus. From Dasya caraibica it differs not only con-
cerning the structure and shape
of the ramuli as mentioned above,
but also by the fact that Acr. opetigenum, so common on Dasya cara-
ibica, was not found on this plant. As the AcrocfaFtium-specios often
are
closely connected to a single species
this indicates furthermore
that this form most probably has nothing to do with Dasya caraibica.
At the islands Dasya caraibica was dredged only in deep water,
about 30
50 meters and in rather open sea in places with strong
currents.
Found
in
the
sound between
St. Thomas
and St. Jan
in
several
places.
4. Dasya
ocellata
(Gratel.)
Harv.
HARVEY
in Hooker,
Brit.
Flora,
vol.
II,
part
I,
p.
335;
Manual,
p.
97;
Phycologia
Brit.,
pi.
40.
KUTZING,
FR.,
Spec.
Alg.,
p.
796.
Tabula'
Phycolog.,
vol. XIV,
pi.
61.
J. AGARDH,
Spec.
Alg.,
vol.
II,
p.
3 ;
p.
1207.
Zanardini,
Icones Phyc.
Adriat.,
pi. 42 A.
FALK.ENBERG, P., Rhodomelaceen,
p.
622,
pi.
18,
figs. 14.
Ceramium ocellatum
Gratel..
Diss.
no.
2,
fig.
II
(non
vidi).
Hutchinsia ocellata Ag.
Syst.,
p.
157.
Dasya simpliciuscula Ag.,
Spec.,
vol.
II.
p.
122.
The
accompanying
figure
(Fig.
325)
of
the apex
of
a main
filament shows the sympodial growth of the plant. We see the vigo-
rous
side-branch
in
the
stage
of bending the apex
of the mother
branch aside, quite in the same way as the last mentioned has pushed
aside the following branch and so on. Of each branch system the basal
-I 'lament only becomes polysiphonous forming a segment in the main
->i
'in
; the remaining parts of the pushed-aside branches form the ramuli.
According to FALKENBERG each branch-system has 5
7 seriate
side-branches,
in my specimens
I have mostly found 5 only. The
lirst side-branch, the one constituting the continuation of the main
ti lament,
is placed upon the first segment, the following upon every
-'< ond one. These branches grow out to long monosiphonous filaments
323
Fig.
325. Dasya
ocellata
(Gratel.) Harv.
Apex of plant.
(About 350:1).
about 15
|ii thick. At the summit of the main filaments the ramuli
are bent upwards covering the growing point
entirely.
The cortical layer is highly developed, covering the stems quite
densely
from
base
to
summit. The
specimens
found
form
dense
dark
red-brown
tufts
about 4 cm high or even
more. They are
richly
ramified
and
on
the
whole
vigorously
de-
veloped.
The breadth
of
the
branch-system
with
the
covering
ra-
muli
is
nearly
a
half
cm.
The
stichidia
are
cylindrical
to
conical,
running
out
in
a
shorter
or
longer
sterile
point.
The
stalk
is
composed
of
1. to
7 or more
cells.
Dasya ocellata was found growing upon the roots
of the mang-
roves to which it is fastened by means of a small disc.
It was growing
in a sheltered locality and in shallow water.
It had tetrasporangia
in the month
of January.
Only found once, St. Thomas: Bovoni Lagoon.
Geogr.
Distrib.:
Bermuda,
Mediterranean Sea,
Morocco, wanner
parts
of the European Atlantic
coast.
5. Dasya
corymbifera
J. Ag.
J. AGARDH,
In Historiam
Alg. Symbol*
(Linnsea,
vol. 16, 1841,
p. 31);
Spec.
Alg.,
vol.
II,
p.
Ill,
p.
1219.
CROUAN,
Fl.
Finistere,
p.
159.
ZANAR-
DINI,
G..
Iconogr. Phyc.
Med.-Adriat.,
vol.
II.
pi.
59.
Dasya orbuscula var. mucilaginosum
Grn.,
Alg.
mar. Finistere, No. 286.
Dasya venusta Harv., Phyc,
Brit.,
pi.
225.
The specimens reach a heigth of about 5
7 cm. They have
5
pericentral cells; the cortex is not much developed, the central cells
being clearly seen through
it.
The ramuli are monosiphonous with
thicker, 50
-60 ^ thick,
cells at their base, thinner upwards, becom-
ing very slender at their summit. The branches
of the ramuli
are
spreading in
all directions.
Tetrasporic plants were the only ones found. The stichidia are
developed on the summit of a branch in the ramuli. They have gene-
21*
324
rally a short stalk composed
of two
cells. The stichidium
is conical
in shape. At the upper end it often runs out in a rather long sterile
monosiphonous prolongation. The stichidia are about 300
ju long and
about
90
|u broad.
This plant was found in shallow water in sheltered places epi-
phytic upon Acanthophora,-. further in the open sea in deeper water
down to a depth of about 30 meters.
It had tetrasporangia in the
month
of March.
St. Groix:
Off Frederikssted.
St. Thomas:
Bovoni Lagoon.
St.
Jan:
off Cruz Bay.
Geogr. Distrib.: West Indies, Atlantic
coast
of Europe and North
Africa, Mediterranean
Sea.
Heterosiphonia Mont.
1.
Heterosiphonia Wurdemanni
(Bail.) Falkenberg.
FALKENBERG,
P., Rhodomelaceen,
p.
638,
pi.
16,
fig.
11.
Dasya Wurdemanni Bailey, HARVEY, Nereis Bor.-Am.,
vol.
II,
p.
64,
tab. XV, C.
KUTZIXG, Tab.
Phycol.,
vol.
XIV.,
pi.
81.
J. AGARDH,
Spec.
Alg.,
vol.
II,
p.
Ill,
p.
1191.
ZANARDIM,
Icon.
Phycol.
Adriat.,
vol.
II,
pi.
53, A.
Cfr. DE
TOIM'S remarks concerning
Dasya
rigidula
(Kiitz.) Ardiss.
in
Sylloge
Alg.,
vol.
IV,
sect.
Ill,
p.
1207.
The
essential
differences
between Heterosiphonia
and Dasya
consist
in
(1) producing two
or more segments
to
the
sympodial
main axis
in each branch-system in Heterosiphonia compared with
the one
in Dasya;
(2)
placing
the
free summits of each branch-
system distichously alternate on both sides of the main axis, and (3)
the
presence
of a more
or
less pronounced
dorsiventrality.
Heterosiphonia Wurdemanni creeps upon larger alga3, stones and
shells and is fastened to the substratum by means of the rhizoid-like
ends or even discs often found in the summit of the branches
(cp.
Figs. 326
, 328 b).
It forms small roundish spongy clumps two to
three cms high.
Because
of
its mostly very squarrose ramification
it becomes
easily entangled between other
algae.
The main branch
carries,
besides the branch constituting the
continuation of the sympodium and placed upon the second segment
of the main branch, another branch issued from the fourth segment.
This branch
is bent upwards,
several times
pseudodichotomically
with divaricate and squarrose branches. Commonly the free
325
part of the branch
is monosiphonous except the basal segment, the
third one
of the whole branch, which
is polysiphonous
; in vigorous
plants the
fourth and
fifth segments, too, are polysiphonous. The
plant
is
quite without
cortex.
FALKENBERG has pointed out that in the Mediterranean Sea he
has found two
different forms namely a robust and very squarrose
Fig.
326.
Heterosiphonia Wurdemanni
(Bail.)
Falkenb.
var.
typica.
ft.
part
of
the
thallus with rhizoids developed from
the summit of the
ramuli.
/?,
transverse
section
of the
thallus.
(a, about 180:1;
b, about
300:1).
form
which
is
like
the
original specimens
of HARVEY from Key
West, and a more slender and
not
so squarrose form. Both forms
have been found
in the West
Indies
(cp.
Figs. 326 and
327).
Fig. 326 gives a representation of apartofthe first-mentioned form.
As seen in the iigure the ramification is very squarrose. The branches
are
rigid,
often curved with obtuse
or acute angles and entangled
between each other. They are composed of rather short
cells, in the
basal part about 60
ju broad and about 70
ju long, tapering evenly
upwards and running out into acute, mostly curved apices
; towards
the top the
cells at the same time become shorter.
In the main axis the segments have 5 pericentral cells in my plants
(Fig. 3266)
; FALKENBERG found 4
6 in his specimens. Of these cells the
three are lying on the upper dorsal side, the two on the ventral side.
The
other form
(cp.
Fig. 327)
is much more
slender and of a
326
softer consistence. The
ramification of the branches
is
scarcer, the
branches are slender with thinner and longer cells
; the unbranched
summit
of the
first branch in the branch-system
is especially much
elongated.
In the basal part
of the monosiphonous ends
of
these
branches the cells are about 40
(a thick and their length about 70
ja.
Towards the top the
cells become somewhat longer (about 120
u),
tapering at the same
time
evenly to the
summit
where
the
breadth is about 25
u.
The
uppermost
end of the filaments
is often a little swol-
len
or
it
becomes
rhizoid-like
(Fig.
328 b).
In
this form the
polysiphonous
axi&
has always
4
peri-
central cells and ne-
ver more (Fig. 328 c).
\Yhile all the gather-
ings of the squarrose
form
were
sterile,,
this one had
stichi-
dia with ripe tetra-
spores
(Fig.
327).
The
stichidia
(Fig.
328 a) are placed at
the ends
of one
of the
ramifications
of the
second
branch. They
are
acute,
subcylindrical
of shape with broadly rounded
base.
In
the
cylindrical
part
they
are
about
110
|u
thick.
They have
a
longer or shorter, monosiphonous stalk composed of a variable num-
lirr
of
cells up to
ten.
My description above proves that the two forms are very different,
and FALKENBERG, too, points out that perhaps we have to do with
two
different
species.
As
they
agree
in
so
many
respects
I
I IT for to consider them only as varieties of the same plant. The first
one, the squarrose form, according to FALKENBERG being like the
l-'i.^. o27. HeterosiphoniaWurdemanni
(Bail.)
Falkb.
y;ir.
Iax.a
n.
var.
t'pper
part
of
the
thalius with
vomit;
stichidia.
'(About
35: 1).
327
original specimens in HARVEY'S Herbarium, must be considered as
the var.
typica. The other more slender and softer plant
I propose
to
call var.
laxa.
FALKENBERG suggests, not having made any observations regard-
ing the localities in which the two forms grow, that the var. typica
ought to
originate from shallow water while the
var.
laxa on the
other hand ought to be a deep sea form. My
observations
have
not
quite
verified
this
supposition. To be sure the var. typicais often
found
in
shallow
water
in
exposed
places
with strong light, but
I
have
also dredged
this form once
in a depth of ten meters and
another
time
in about twenty
meters.
As
to the var. laxa this was once found in shal-
low water in a lagoon growing in the shade
of the mangroves and therefore at a place where
it might be exspected to occur, but another
time it w
ras gathered in shallow water behind
Long Reef at Christianssted, a rather exposed
place with strong light.
The specimens with tetraspores were ga-
thered in the month of
January.
HeterosiphoniaWurdemanniis often found
rig.
6'2b. Heterosipnonia
upon other larger algse. Between its branches
Wurdemanni
(Bail.)
Falkenbergia Hillebrandii
is often entangled.
Falkb
var. Zoara
n. yar.
a, sticniaium with
rip<-
Heterosiphoma
is most probably a com-
tetrasporang-ia
;
in
the
mon species along the shores of the islands
;
k.asal P art the^ are emP~
tied,
b, ends
ot ramuli
I have gathered
it only at the shores of St.
transformed
into
rhi-
P roix
zoids.
c, transverse sec-
tion of the
thallus.
St.
Croix:
Christianssted s
Lagoon,
Long
(About
180:1).
Reef, White Bay, Casavagarden.
Geogr. Distrib.: West
Indies, Key West, Cadiz, Mediterranean Sea.
Dictyurus Bory.
1.
Dictyurus
occiden tails
J. Ag.
AGARDH.
J., Nya alger
fran
Mexico
(Ofversigt
af Kungl. Vet.-Akad.
l-Y.i-handl.,
1847,
p.
17); Spec.
Alg.,
vol.
11,3,
p.
1243.
KUTZING,
F., Spec.
Alg.,
p.
673; Tab.
phycol.,
vol.
XII,
t.
64.
Unfortunately
all
the
material
preserved
in
spirit
of
this
328
highly interesting plant seems to have been gathered in a season
where the plant had stopped
its growth, as no young branches or
summits of
thallus are to be found in the material brought home.
Therefore
I am able to give only a rather fragmentary description
of the construction of this plant which FALKENBEKG just mentions.
On the other hand, FALKENBERG gives
a very detailed description
of the old world species, Dictyurus purpurascens.
Dictyurus occidentalis forms dense tufts, up to 10 cm or more
and
is fastened to the substratum, rocks, stones
etc. by means
of
small discs and rhizoids growing out from the basal part of the stem.
This often very irregularly shaped base, from which new erect stems
arise, grows together with bases of the neighbouring plants forming in
this way rather large tufts. From this basal part
the
erect more
or less branched shoot-systems
arise. These are mostly bare
in the lower part
bearing
merely
the
remaining
basal
parts
of
the
aside-pushed
free
ends
of
the
branch-
systems of which the plant is constructed. These
remnants are found alternately and distichously
on both sides of the terete stem. Higher up we
Fig.
329.
Dictyurus
fm(j
t jle
characteristic
reticular
tissue
origina-
occidentalis
J. Ag.
Transverse section
ting
from
the
upper
ends
ol
the
pushed
of the mam stem.
asi(je
free
branches
of
the
svmpodium
sur-
( About
bU: 1).
rounding
the
central stem
like a closed
spiral
staircase. A transverse section of the stem shows four pericentral
cells surrounded by a thick cortical layer
(Fig.
329).
As
Dicli/iirns
occidentalis, with regard
to
the
fully
developed
tissue, bears such a close resemblance to Dictyurus purpurascens
I
feel
quite convinced that
its development
takes
place
in
a very
similar way.
In Dictyurus purpurascens we have,
as
described by
FALKENBERG, sympodial growth of such a kind that the branch which
constitutes the continuation of the main axis is developed upon the
second segment of the mother branch, giving in this way two seg-
ments to the sympodial stem. Besides this
first branch whose pur-
pose is the continuation of the sympodium, the branch pushed aside
bears yet three side-branches. These three branches are sympodially
ramified so that each branch-system bears only a single side-branch,
namely that intended for constituting the continuation of the axis.
This branch is placed upon the second segment of the mother branch
320
and, as the ends of each of the branches are placed distichously alter-
nately on both sides of the main axis, the whole sympodium gets a
very regular, feather-like appearance. An exception from this rami-
fication is only made by the second side-branch (the first of the three)
this being firstly branched once, the two branches originating from
this branching are then sympodially ramified in the way described
above. FALKENBERG gives very fine illustrations
(1. c., pi. 17 figs. 13,
14) of these lateral sympodia. The main axes of these four sympodially
ramified branch systems become polysiphonous with the exception
of their uppermost ends. From the monosiphonous side-branches of
these lateral sympodia the net
is developed. This is formed in such
a manner that outgrowths emerge from two neighbouring filaments
and grow together after which the outgrowths are separated by walls
from the mother-cells. But this growing-together process
is not
re-
stricted to filaments from the same group of sympodia, for the peri-
pheral filaments of one group of sympodia connect themselves with
those
of other groups
(cp.
Fig. 331 a).
Fig. 330 a shows a transverse section
of
the
thallus
of
Dicty-
ums occidentalis. This is seen to be quadrangular with concave sides
;
but, because of the spiral arrangement of the net, this is cut through
and wanting at the one side, and further, because of the very thick
cortical layer of the main stem, the base of the two branch systems,
drawn in the figure, is not clearly seen. When FALKENBERG, regarding
Dictyums occidentalis, says, I.e.,
p. 681, Mass an
dieser iiberhaupt
schwacheren und schlankeren Dictyurus-Art die Hauptaxen der Sei-
tensympodien
an der
sterilen Pflanze wenigstens
durchweg
monosiphon bleiben" it does not correspond with my observation (cp.
Fig.
3306)
the main
axes
in my specimens
being polysiphonous
with four pericentral cells. It is only in small and very feebly developed
branches that
I have found the side-branches throughout monosi-
phonous. And besides
it
is so in the case of the original specimens
from Mexico, at any rate in that specimen
I have examined. Of the
four main axes in each branch-system the two run out in the pro-
longed corner of the net, the other two end in about the middle of
the concave side (Fig. 330 a). And here Dictyums occidentalis shows
a marked difference from Dictyums purpurascens according to FAL-
KENBERG'S
description.
In
the
latter
we
have
between
the
larger acute corners smaller obtuse edges to which the polysiphonous
axes run out. This I have not found in my material
; between the high-
330
ly protruding four corners the sides of the net are evenly concavely
rounded with no
processes
or edges
in
their middle
(Fig.
330 a).
The edges protrude into rather long, at the farthest end nearly cylin-
drical, elongations with a large, circular opening; the borders of these
are adorned by small acute processes (Fig. 330 a). The very protru-
ding corners make the edges of the plant highly sinuate (Fig. 331 b).
Fig. 330.
Dictyurus
occidentalis
J. Ag.
a,
transverse section
of the
thallus (comp.
text).
I), part
of the plurisiphonous main
axes.
(a, about
10:1,
b,
100:1).
Fig. 331 a
shows a part
of a poorly developed shoot.
In
this
the growing-together of the summit of the filament in one branch-
system with the filaments of another one above is clearly demonstra-
ted.
The
cells
in the net
are about
60
70
ju thick and 1% times
as
long.
All the
material gathered was
sterile.
I have been able to compare my specimens with the
original
material of this species, collected atVeraCruzbyLiEBMAN and being
preserved in the Botanical Museum, Copenhagen.
The
original spe-
cimens belong to a very small and tiny form reaching a heighth of
about 5 cm only. As mentioned above the axes
of the sympodia,
bearing the net, are, in the specimens I have examined, monosiphonous.
331
This plant has been found partly in shallow water (about one
meter) in a rather exposed place and partly in deep sea at a dapth
of about 30 meters.
St. Croix: White Bay. St. Tho-
mas:
In
the
sea
to
the west
of Water
Island.
Geogr.
Distrib.:
Mexico,
West
ndies.
Some new
199).
GOL-
Fig. 331.
Dictyurus
occidentalis
J. Ag.
a, part
of
a small poorly developed erect shoot showing the growing
together
of the
net.
6,
part
of the
thallus.
(a, about 20:1;
b,
6:1).
Genera incertae sedis.
Falkenbergia Schmilz.
1.
Falkenbergia Hillebrandii (Bornet) Falkenb.
FALKENBERG,
P.,
Rhodomelaceen,
p.
689.
BORGESEX,
F.
or
little known W.
I.
Florideee.
II,
(Bot.
Tidsskr.,
vol.
30,
p.
LINS and HERVEY, AJg. Bermuda,
p.
122.
Polysiphonia Hillebrandii
Bornet
in ARDISSONE,
Phycologia Mediter-
ranea,
I,
p.
376.
The genus Falkenbergia is remarkable for its 3 pericentral cells and
especially for its way of branching, this being, as pointed out by FAL-
KENBERG, very different from the two ordinary ways of branching,
either exogenous or endogenous, in the Rhodomelacex. The branching
takes
place
in
such a manner
that a cupola-formed outgrowth
is
given off from the middle
of one
of the pericentral cells
; this out-
growth
is soon separated from the mother cell by a wedge-shaped
wall becoming the
apical
cell of the new branch
(Fig. 332 c). The
332
basal cell, the remaining part of the
pericentral cell,
is divided into
a
central and three
pericentral
cells becoming the
basal segment
of the branch (Fig. 332 d). In this way the branch is placed upon the
middle of a segment and not near the upper walls between the
seg-
ments
as always
in the
case
of the Rhodomelaceae.
The growth in length of the filaments takes place with the aid
of a rather large conical apical cell (Fig. 332 a), from which the lowest
part
is gradually
cut
off by means
of a ho-
rizontal wall into
flat,
disc-like
segments.
These cells are again di-
vided by vertical walls
into the small
central
cell and the three peri-
central
cells.
Epiphytic upon other
algse,
the
irregularly
ramified
and
twisted
filaments of Falkenber-
gia Hillebrandii
forms
densely
matted
tufts
up to a height of two
to three cm. The rami-
fication is very irregular
(Fig. 333 A), rather long
parts
of the
filaments
often being undivided,
whilst in other ones the
Fig. 332. Falkenbergia Hillebrandii (Bornet) Falkb.
a, summit
of a filament,
b, part
of a moniliform
filament,
c and
d, branching of filaments.
(About
270:1).
ramifications occur close together
; large spongy clumps being formed
in this way.
It
is fixed to the host plant by means
of irregularly
shaped,
often
disc-like
haptera
(Fig.
333 F,
G)
emerging
from
the lowest, more
or
less horizontally growing filaments. These
as
well as the haptera are
thick-walled in contrast
to
the otherwise
rather thin walls of the thallus.
There was not any kind
of reproductive organs found in my
specimens; COLLINS has succeeded in finding tetraspores. According
to him
they are tripartitely divided and formed from one of the peri-
central cells of a ramulus quite as in Polysiphonia, but occurred singly
not in series".
In Falkenbergia vagabunda the sporangia are formed
directly from a pericentral cell and no covering cells are present. The
contents
are
firstly
divided
in two parts and these two parts
are
again divided into the four spores
(cfr. FALKENBERG,
1. c.,
p. 691).
While the form
first discovered by me and mentioned in my
paper quoted above was rather a small one, the filaments reaching
only a diame-
ter
of
about
3040
n,
I
have
later on
found a much
more
robust
form in w
rhich
the
filaments
often
had
a
diameter of 50
to 60 u. In this
Fig. 333. Falkenbergia Hillebrandii (Bornet)
Falkb.
A, part
of the
thallus
(25:1). B and
C, summits
of
fila-
ments,
in B with
a new branch (150:1).
Z>, part of a
fila-
ment
(120:1). E, transverse section of the
thallus
(150:1).
F and
G, hapters
(65: 1).
form
the
seg-
ments were
now and then
very
swollen
in their middle, the whole filament in this way getting a moniliform
appearance
(Fig. 332 &)*).
This species occurs in shallow water near the shore in sheltered
as well as in more exposed places.
It
is, as mentioned above, found
epiphytic on or intertwisted among other littoral algse as Gelidium,
Chamsedoris
annulata,
Heterosiphonia Wurdemanni, Dasya
ocellata
etc. often forming together with these large spongy tufts.
At the islands
it seems
to be a common
species.
Geogr. Distrib.: Mediterranean Sea, Canary islands, Bermudas, Bar-
badoes.
Cottoniella nov. gen.**)
Thallus ex filamentis infra decumbentibus rhizoideis substrato
adfixis, dein assurgentibus,
erectis compositus, structura dorsiven-
According to YENDO
(Bot. Magaz.,
vol. XXX,
p. 62) our -form
is very
like the Australian F. rufolanosa (Harv.) Schmitz; most probably
this
plant and
F.
Hillebrandii are forms
of the same
species.
I have great pleasure
in naming
this interesting plant
after my Eng-
lish colleague and
friend, Mr.
A.
D. COTTON
of Kew.
334
traJi, subcomplanatus,in juvenili statu ex una cellula central! et quat-
tuor pericentralibus compositus, postea cortice tectus.
Crescentia terminalis; cellula apicalis major, transverse septata.
Filamenta in inferior! parte decumbentia, rhizoideis substrato adfixa
dein assurgentia, subrecta, in superiori parte arcuata.
Thallus infra nudus, supra in latere
dorsali (convexo) ramulis
monosiphoneis in duas series alternantibus, instructus. Celluke ramu-
lorum
cylindrical.
Ramificatio adventitia, ramis ssepe prope ab latere ramulorum
ortis.
1.
Cottoniella arcuata nov.
spec.
Frons
ca.
8 cm alta. Kami adulti
ca. 200
250
(LI
lati, ramulis
usque ad
1 mm longis, ex
cellulis cylindraceis
ca.
175
|u longis
et
7
20
|a
latis
compositis.
The basal part
of the
plant
consists
of decumbent
filaments
fixed to the substratum (Halimeda etc.) by means of rhizoids
(Fig.
3366). The rhizoids are not separated by walls at their outgrowth
from
the
mother-cell,
but
walls
occur in the more
or
less
cylin-
drical stalk; they end in a small multilobed disc. The rhizoids are
rather vigorous with thick undulated walls; the cylindrical part
is
about 30
|u; the wall about 12
ju broad.
The decumbent filaments show no marked differences from the
erect ones, their summits often bending upwards and those
of the
erect
filaments bending downwards. The decumbent
filaments
as
well as the erect ones with the exception of the youngest parts are
covered by a cortical layer. The thickest filaments
I have met with
had a diameter of 200
250
u.
The
erect
filaments
are
arch-shaped
in
their
upper
ends
(Fig.
334),
bearing
a
series
of
branchlets
with
limited
growth
placed in zigzag in two rows along the dorsal, convex sides (336 a}.
The filaments increase by means of a large, conical-cylindrical
apical
cell
(Fig.
335 a,
b) from which
disc-shaped,
thin segments
gradually are cut
off.
These segments remain undivided
for some
time,
I have counted about 6 of them. They increase gradually in
length and are then divided into a central and four pericentral
cells.
Shortly after the segments have begun to be divided the branchlets
with limited growth begin to grow out from the central cells (Fig.
.'!.'!.") a, b} and are seen as small cupola-outgrowths on the convex side
335
of the filaments. A branchlet is given off from each segment so, that
they are placed alternately on both sides of the median line of the
main branch forming in this
way two series on both sides
of
it
upon
the
dorsal
side
of
the branch
(Fig.
336 a).
The branchlets tend to-
wards
the
top
(Figs.
334,
335a) issuing from the mother
branch
with
acute
angles;
they
are
monosiphonous,
unbranched and, when
fully
developed, composed of long
cylindrical
cells
about 20
f.i
thick and
often more
than
10 times as long, only taper-
ing
slightly
towards
the
summit. The whole branchlet
reaches
a
length
of
about
1200 u. The basal cell in the
branchlets
is
short,
nearly
quadratic, and becomes more
or less immersed in the cor-
tical layer
; the summit of the
branchlet
is
obtuse.
The
branchlets
are rather
persi-
stent
; in the older, lower part
of
the
filaments
they
are
dropped,
leaving
only
the
basal cells.
At some
distance from
the summit when the branch-
letb are already much devel-
oped the adventitious bran-
ches with continuous growth
are formed
(Figs. 334,
335 a).
These
contribute
to the
ramifica-
tion
of the plant and
are issued now and then without any more
definite distance between them. They are mostly issued at the side
of a branchlet (Fig. 335 c).
I have most frequently found them placed
Fig. 334.
CoUoniclla
arcuntu
nov.
spec.
Upper parts
of filaments.
(About
45:1).
330
Kig
1
. 335.
Cottoniella arcuaia nov.
spec.
a, upper
part
of
a filament with branchlets and a young branch,
b, summit
of a filament
showing
the
endogenous
origin
of the
branchlets.
c, branch
issued
at
the
side
of a branchlet.
d,
base
of a branch,
e,
/',
g,
transverse
sections
of the
thallus.
(a, about
220:1.
b,
450:1.
c and
d,
320:1. eg,
250:1).
on the left side of the branchlet, but probably this is only by chance,
for
I have also found them placed on the right side
; sometimes, too,
a branch happens to be issued from a segment without any branchlet.
In the
first
stage
of development the branches
are very
like the
branchlets, but longitudinal walls are soon developed, dividing the
segment
into
a
central and
four
pericentral
cells.
The segments are, immediately after they are cut
off from the
apical cell, very short, but gradually they increase in length becoming
337
in the
full grown filaments about
2
4 times as long as broad
:
for
instance a filament was 50
JLI thick and the segments 150 ^ long.
The
dorsiventrality which
is
clearly expressed by the curved
summit of the plant and by the arrangement of the branchlets upon
the convex dorsal side of the filaments is also seen upon the trans-
verse section of the filaments, these having a more or less pronounced
bilateral appearance
(Fig.
335 e
g). The older parts
of the plant
become,
as mentio-
ned above, gradually
covered by a corti-
cal
layer.
In
the
younger parts of the
filaments
this
does
not form any coher-
ent
layer;
in
the
older parts, especial-
ly in the basal
fila-
ments, it covers the
whole filament den-
sely.
In
spite
of a
thorough
search
I
have not succeeded
in finding any young
stages showing
the
development, but
I
think
we
have
to
do
with
a
cortical
layer formed by hy-
phse.
The
fig. 336 c
shows the
first
sta-
ges
found.
At
the
top on the left side
of the figure a hypha has grown down from the
uppermost pericentral
cell and,
after having passed a segment,
it
has grown together with the upper end of the pericentral cell of the
next segment being at the same time divided into two
cells.
On
the
right
side
of the
figure another hypha has grown down along
two segments and has been divided into
4
cells.
It is much to be regretted that there was not found any kind of
22
Fig. 336.
Cottoniella arcuata nov.
spec,
a, 'summit
of a filament
seen from the
dorsal
side,
showing the
zig-zag arrangement
of the branchlets.
b, part of a decumbent filament with rhizoids.
c, part
of a filament showing
the
development
of the
cor-
tical
layer.
(a, about 350:1.
6,
80:1.
c,
240:1).
338
reproductive organs among the specimens collected, these being quite
sterile.
If we now ask to which of the forms of Rhodomelacese our plant
come nearest this question
is, of course,
difficult to answer as long
as we do not know its reproductive organs. We must surely look for
its
nearest
relatives amongst the dorsiventral forms
of the Rhodo-
melacese, even if it does not seem to be so very closely related to any
of the known forms. The arrangement of its branchlets in two rows
on the dorsal side of the stem bears a resemblance to that in
Clif-
tonia. We ought
also to compare
it with forms
of Bostrychia and
related genera.
It was found
in very
small
quantities
intermingled between
the Callithamnion
spec, mentioned above on
p. 2201.
Only dredged once in deep sea at a depth of about 20 fathoms.
St. Thomas.
In
the
sea
to
the
west
of Water
Island:
off
Great
Crum Bay.
Fam.
3.
Delesseriacece.
Subf'am.
1. Sarconemieae.
Taenioma
J. Ag.
1. Taenioma perpusillum
J. Ag.
AGARDH,
J., Nya
alger
fran Mexico
(Givers,
k. Vet.-Akad. Forhandl.,
1847);
Spec.
Alg.,
vol.
II,
p.
3,
p.
1257.
Taenioma
macrourum
Thuret
in
BORNET
et THURET,
Notes
algolog.,
fasc.
1,
pag.
69,
pi. XXV.
FALKENBERG,
P.,
Rhodomelaceen,
p.
709,
pi.
15,
figs. 2129.
Polysiphonia nana
Klitz., Tab.
phycol.,
vol.
XIII,
p.
10,
pi.
29.
Already in "Notes algologiques"
THURET expressed his doubt
as to the specific difference between the Mediterranean form and the
Pacific one. In "Les Algues de P. K. A. SCHOUSBOE" BORNET, after
having examined specimens of Tsenioma perpusillum, arrives at the
conclusion that the two species cannot be distinguished from each
others. On the other hand FALKENBERG,
1. c. p. 709, maintains the
difference between the two plants basing his conclusion
especially
upon the non-existence in Taenioma perpusillum of the long monosi-
phonous hair-like filaments which crown the summits of the branch-
lets in Tsenioma macrourum.
Not having had any specimens of the
339
Pacific form at my dis-
posal because the ones
collected by LIEBMAN
most
probabl y
have
been
kept
in
J.
AGARDH'S
Herbarium
in
Lund,
I have not
been able
to compare
the two plants, but I am
most inclined to think
that BORNET
is
right.
The
structure
of
this
plant
has
been
examined by FALKEN-
BERG,
1. c.
In its way of grow-
ing
it
bears
a
close
resemblance to Herposi-
phonia
tenella
having
a
creeping,
prostrate
main stem with indefi-
nite growth from which
erect
branches
arise
(Fig. 337 a). The main
stem
is
terete
and
a
transverse
section
shows four
pericentral
cells. From its ventral
side rhizoids are issued
downwards
; these often
have a long stalk with
no
walls
or
a
few-
ones, ending in a small
more or less lobed disc.
On
its dorsal side
the main stem carries
more
or
less
ramified
branches with
definite
growth and
placed
in
Fig.
337. Tsenioma perpusilluin
J. Ag.
part
of a plant,
b,
upper
part
of
the
flat
branchlet with basal part
of the
hairs.
(a, about 30:1,
b,
270:1).
22*
340
two rows'; now and then one of these branches get indefinite growth
contributing
in
this way to the
ramification
of the
plant.
The main stem increases by means of an apical cell from which
flat segments are cut
off gradually:
from these the branches grow
out, even before the segments are divided. The branches in my plant
issue mostly from every sixth segment, and it is only in a very few
and rare cases that the space between the branches may be either
shorter or longer than the above mentioned. FALKENBERG found, in
his Mediterranean plant, about four segments between the branches.
The segments are first divided into two cells, one large and one small,
and in such a way that the first wall is formed underneath the inser-
tion of the branch; the next wall, dividing the large
cell, is formed
opposite to it, the segment by these divisions being divided into three
cells, a larger
cell in the middle and two
smaller peripheral ones
on both sides. Then finally the cell in the middle is divided by two
walls
in
a
central and two
opposite
peripheral
cells.
It
is a
well
known fact that this plant has previously been included among the
Rhodomelacex*},
but
the
above-described way
of
cell-division
is
quite in concord with that found
in the Delesseriacese and differing
from that
in the
Rhodomelacese.
Compare
in
this connection
the
schematic figures of both kinds of division given by FALKENBERG,
1. c., p. 4. The main stem in the upward growing branches is terete
like that of the prostrate main axis. The branches carry mostly 3
4
branchlets; but now and then in more weakly developed plants the
erect branches are reduced to a single branchlet.
The
final shape
of the
branchlets
is
flat.
The lowest segments of the
branchlets remain
terete:
but
in
the
following segments
the two
opposite
peripheral
cells become
divided in such a way that first a smaller cell is cut off in the upper
peripheric corner by a convex wall and then a similar
cell is cut
off in the
corner below
(cp.
Fig. 337 b).
No
further
divisions do
take place. This division of the cells is quite in agreement with that
found in other
Delesseriacese.
The branchlets are not ramified until a side-branch
is formed
at rather definite distance from their base (about 15 segments).
The
apical
cell
of this one gets the same
or nearly the same
strength and the same
direction
as that
of the mother-axis. Both
Compare FALKENBERG,
I.e.,
p.
708.
341
cells are divided in a similar way giving origin to the two long hair-
like
filaments crowning the
branchlets
(Fig. 3376). At the base
oi'
the hairs short segments
are
cut
off;
these grow longer upwards,
become hair-like without chromatophores, the uppermost ends of the
hairs dying away gradually.
It cannot be denied that these terminally
placed hairs bear a close resemblance to those
of the Phseosporacese
having a very similar intercalary
division. The growing point
lies
a little above the bifurcation, the segments being shortest here and
always
filled
densely with protoplasma
etc.
My specimens are all sterile. The stichidia are beautifully figured
by THURET,
1. c. The sporangia are formed in two rows in the
flat
branchlets in the remaining part
of the two
pericentral cells from
which the two border-cells are cut
off.
The cystocarps are unknown. COLLINS and HERVEY*) mention
that they have found a mature
cystocarp,
but
it was lost before
notes and figures could be made.
The plant was found in an open place upon reefs of calcareous
algae
etc. with shallow water or nearly laid
dry.
St. Jan: Cruz Bay.
Geogr. Distrib.:
Pacific Ocean, West Indies, Cape, Morocco, Mediter-
ranean Sea, Tongatabou.
Seems
to be widely spread
in warmer
seas.
Caloglossa
J. Ag.
1.
Caloglossa
Leprieurii
(Mont.)
J. Ag.
AGARDH,
J.,
Epicrisis,
p.
499.
CRAMER,
C.,
Uber
Caloglossa
Lepri-
eurii (Mont., Harv.)
J. Ag. in Festschrift
f. NAGELI u. KOLLIKER, Zurich 1891.
Delesseria
Leprieurii
Mont.
Seconde
Centurie de
plantes
cell,
exotiq.
nouvelles
in
Ann.
Sc.
Nat.,
Bot.,
II.
ser.,
t.
13,
p.
196,
pi.
5,
fig.
1.
J.
AGARDH, Spec.
Alg.,
vol.11,
p.
682. HARVEY, W. H., Nereis Bor.-Am., Part
II,
p.
98,
pi. XXII.
C.
Hypoglossum Leprieurii
Kiitz., Spec. Alg.,
p.
875; Tab. phycolog.,
vol.
XVI,
tab.
10.
NAGELI,
C., Wachsthumsgeschichte von Hypoglossum Lepri-
eurii (Mont.)
Kg.
in NAGELI und
C. CRAMER, Pflanzenphys.
Untersuch.,
1.
Heft.
1855,
p.
69,
tab.
VIII.
This specieshas been examined several times, especially by NAGELI
and CRAMER, to whose beautifully illustrated examinations I here refer.
Caloglossa Leprieurii
(Fig. 338)
is one
of the
algaB commonly
occurring on the roots of the mangroves, upon which it often forms
*) COLLINS,
F. S. and A. HERVEY,
Algae
of Bermuda,
p.
117.
342
dense tufts.
Its flat, leaflike thallus is thin, consisting, with the ex-
ception of the midrib, of only a single layer of cells;
it
is repeatedly
forked and narrowed at each ramification, the internodes, on account
of
this narrowing,
being lanceolate.
One
of
the
flat
sides
of the
thallus
is turned upwards, the
other downwards
against the sub-
stratum. From the side turned down rhizoids are issued at the fork-
ings of the thallus (Fig. 338). Small epidermal cells are cut off from
a group of central cells at the forkings, cp. NAGELI, 1855,
1. c., p. 73,
pi. VIII,
figs.
1 and
7.
From these
cells a bundle of rhizoids grow
Fig. 338.
Caloglossa Lcprieurii (MontJ
J.
Ag.
Part
of
a plant.
(About
6:1).
out, cohering more or
less
at their outgrowth,
later on separating
and spreading out in
all directions. By means of these haptera the
plant
is
fixed
to
the
substratum.
I have not come across tetrasporangia in my material, but tetra-
sporic plants and the structure of the tetrasporangia have been de-
scribed by CRAMER,
1. c. The
tetrasporangia
are formed
in
great
number in a single layer in the tissue on both sides of the midrib.
In the
part
of the
thallus
destined to produce the tetrasporangia
the cell-division takes place in a way somewhat differing from that
in the vegetative
thallus. The primary marginal
cells form only a
single row of
cells; these
cells are later divided into two
cells: one
above, namely the mother cell of the tetrasporangia, and one below
343
which remains vegetative. Gradually, as thetetrasporangium increases
in size, the
last mentioned
cell becomes slender and curved round
the
tetrasporangia
;
it
gets a semilunar shape and
its upper end
becomes
connected with
the
cell
above.
In
this way
a
reticular
tissue of vegetative
cells
is formed connecting the midrib with the
not fructiferous margi-
nal cells of the thallus.
The
antheridial
stands have previously
been found by CRAMER.
I have come
across
a
few male plants in my
material.
When CRA-
MER
remarks that
he
has found
the
anthe-
ridial
stands
upon
"kleinen Ceylonpflanz-
chen", my plants were
by no means especially
diminutive, on the con-
trary the thallus of the
male plant was even lar-
ger than that of the fem-
ale, at any case broad-
er.
In the male plant
the breadth of the thal-
lus was two mm, in the
female onl
about 1%
Fig.
33!>.
Caloglossa Leprieurii (Mont.)
J. Ag.
Part
of
a male plant with
antheridial
stands.
(About
30:1).
mm.
The
antheridial
stands (Fig. 339) occur
in the upper parts of the
thallus as large coverings upon both sides of the thallus leaving the
midrib
free and mostly, too, a narrow belt of vegetative
cells along
the edge of the thallus. The cell-division in the male plant takes place
in nearly the same way as that in the vegetative one, only the cells
forming the
tissue being smaller. From the
surface
of these
cells
about 2
4 small cells originate from which the spermatia are cut off.
As
to the cystocarps
I have only found a few.
As described by
344
CRAMER, they occur upon the midrib of the thallus. They are spherical
of shape about 460
jii broad. CRAMER maintains that the cystocarps
occur upon the underside of the thallus. This
I have not been able
to verify in my material,
the
small
pieces found
with
cystocarps
being without
rhizoids.
As mentioned above this species occurs upon the roots of the
mangroves
under
whose
shade
it
is
able
to
grow, even
some-
what above the
sin face
of the
sea.
Like
several Bostrychia-sipQcies
it olten lives, too, in brackish and dirty water. According to HARVEY it
is even found
in
rivers
in Georgia and Florida and M. A. HOWE*)
came across this plant in a mountain stream in Porto Rico. The lo-
cality was about 12 kilometers from the sea and the elevation about
400 to 500 meters. ZANARDINI, GOEBEL and KARSTEN have described
related
species from Borneo, Zanzibar and the island
of Amboina
all
living in
fresh water.
This species has been found
at
St. Croix:
Christianssted's
Lagoon,
Salt River Lagoon.
Geogr. Distrib.:
Seems
to
be widely
distributed
in warmer
seas.
Subfam.
2.
Delesserieae.
Delesseria Lamour.
1.
Delesseria
teuuifolia Harv.
HARVEY, W. H., Nereis Bor.-Am.,
II, p. 97,
pi. XXII, B.
KUTZING, F.,
Tab.
Phycol.,
vol. XIX,
tab.
13,
figs,
d, e,
f. AGARDH,
J..
Epicrisis,
p. 488.
Hypoglossum tenuifolium
J. AGARDH,
Spec,
Alg.,
vol.
3, pars
3,
1898,
p.
186.
B0RGESEN,
F., Some new
or
little known West
Indian
Florideae.
II,
p.
198.
This fine, delicate plant (Fig. 340) forms dense bushes up to ten
cm or even more. When alive it mostly had a bright yellow-greenish
colour, but when dried
it got a reddish tinge.
It has a shorter or
longer basal stem up to 1 cm long, from which the densely ramified
often nearly globular, thallus
arises. The stem consists of the
first
developed
leaf
of the young
plant, whose
cells have grown
large
with thick walls, but this has further been strengthened by means
of a parenchymatous tissue, forming on both sides of it a semicircular
tissue
(cp.
Fig.
341 a).
*) HOWE, M. A.,
Caloglossa Leprieurii
in mountain streams (Torreya. vol.
2.
1902,
p.
149).
345
At the base
the stem
produces
irregular bundles
of
rhizoids,
which gradually separate, fixing themselves to stones, shells, coralline
alga?
etc.
The single leat of the thallus is linear-lanceolate
of shape with
an obtuse, generally emarginate apex. It consists of only a single layer
of
cells, with the exception of the midrib in which three layers are
found
(Fig. 342 C), namely a smaller, nearly quadratic central
cell
and two larger, peripheric cells.
From
this
midrib
proliferous
young
leaves
are
repeatedly
issued
(Fig.
340),
the
ramifi-
cation
of
the
thallus
being
formed
in
this way.
In the
older
part
of
the
thallus the midrib and nearest
surrounding
cells
of
the
leaf
become strengthened by rhizo-
ids growing out from the basal
cells
of the
proliferous
leaves.
Gradually
in
approaching
the
base
these
rhi-
zoids form a parenchymatous tissue which becomes
thicker and thicker
until
it, as mentioned
above,
becomes
in strong
plants
nearly
semiglobular
in
the basal stem
(Fig. 341 a).
The
thallus
increases by means
of an
apical
cell from] which semicircular segments are
cut
off
Fig- 340. Delessena
/n-
0/1-1
L\
T-i-
j-
-j
tenuifolia Harv.
(.big. 341 0).
Ine segments are divided
in
a
cen-
p art
O f a
female
tral and two marginal
cells.
It
is
a
well known
plant with crysto-
fact, mentioned already, by NAGELI and SCHWENDE-
(About
4:1).
NER*), that the thallus of the Delesseriacezeis built up
by means of filaments congenitally connate. From the
central axis
opposite, biseriate filaments
aie
issuing.
These
filaments are unil-
aterally
ramified,
the
branchlets
issuing
from
their
underside.
In our plant, cp. Fig. 341 0, the
first side-branch
is usually issuing
from the large cells on both side of the midrib and, sometimes, from
one of the following cells in the filaments still one more side-branch
is given off in other filaments the branching first takes place from the
*) Das Mikroskop,
2te
Aufl.
1877,
p.
561.
346
a.
Fig. 341.
Delesseria
tenuifolia Harv.
transverse section
of older
leaf,
b, summit
of a
leaf,
c,
a young
leaf.
\d, middle part
ot
the
leaf of tetrasporic
plant,
(a, about
45:1.
b,
270:1.
c,
250:1.
d,
120:1).
Fig. 342.
Delesseria
tenuifolia Harv.
A,
part
of the
leaf of an antheridial
plant
(120:1).
B,
transverse
section
of
antheridial
stand
(270:1).
C,
transverse
section
of
the midrib
of the
leaf
(120:1).
347
second or third
cell in the filaments, and filaments occur which are
not branched
at
all. NIENBURG*),
in
his paper on the construction
of the thallus
of the
Delesseriaceae, has pointed out
(1.
c.,
p.
205,
6,
figs.
43,
44) that we have two principal ways of ramification
in
this family.
Of these our plant agrees with the Hypoglossum-tjpe as
found in Delesseria Hypoglossum.
As I have already mentioned in my paper quoted above, tetra-
sporic
as well as antheridial and cystocarpic plants were found in
my
collection.
The
tetrasporangia
(Fig.
341 d]
occur
close
to the midrib, symmetri-
cally
arranged
on
both
sides of it. Their develop-
ment begins at about the
middle
of
the
leaf
and
continues
upwards,
the
tetrasporangia being
younger and younger to-
wards
the summit.
The antheridial stands
(Fig. 342^4) are placed on
both
sides
of the midrib
of the
leaf forming
low,
dense cushions. They are
arranged rather regularly,
generally
following
the
main
filament
in
each
of
the
branch-systems
of which
the
leaf
consists, leaving in
this way the side-branch bare, but
it happens
that some
of the
cells in
these, too,
are covered with
antheridia,
some
larger
tufts being formed
in this way.
The arrangement
of
the
antheridial
stands
bears
rather
a
close
resemblance
to
that
found
in
Delesseria
ruscifolia,
cp.
BUFFHAM**).
The
cystocarps
(Fig. 343) are urn-shaped and
issuing from the midrib
of the
leaf.
Fig. 343.
Delesseria tenuifolia Harv.
A nearly ripe cystocarp.
(About
80:1).
*) NIENBURG, W.,
Zur Keimungs-
und Wachstumsgeschichte
der
Deles-
seriaceen.
(Botanische
Zeitung,
1908).
**) BUFFHAM,
P.
H., On
the
antheridia,
etc.
of some
Florideae (Journal
of the Quekett microscop. Club., vol. V, ser. II, 1893, p. 6, pi. LXIV, fig. 25 1.
348
This plant was found with tetraspores,
antheridia and
cysto-
carps
in the month
of March.
It was dredged in deep water about 30
40 meters and in a place
where strong currents
prevail.
St.
Jan:
In
the
sound
between
this
island
and
St. Thomas:
off
Cruz Bay.
Geogr. Distrib.:
Florida.
Subfam.
3.
Nitophylleae.
Martensia
Bering.
1.
Martensia Pavonia
J. Ag.
J. AGARDH,
Spec.
Alg.,
vol.
II,
p.
Ill,
p.
831.
KUTZING,
F.,
Tabula?
Phycol.,
vol. XIX,
tab.
60,
figs,
e
n.
SVEDELIUS,
N., Uber den Bau und
die Entwicklung
der
Florideengattung
Martensia
(K.
Sv. Vetenskapsakad.
Handl., Band
43, No.
7, Uppsala
1908).
Mesotrema
Pavonia
J.
Ag., Nya
algformer
in
Ofvers.
k.
Vetensk.
Akad.
FOrhandl.,
1854,
p.
110.
SVEDELIUS in his very valuable work on the genus Martensia
gives an exhaustive description
of the present species based partly
upon material collected by me at the island
of
St. Croix.
Having now examined some more collections of mine of this plant
I am able to add
a few remarks to SVEDELIUS'
description.
Martensia Pavonia grows epiphythic upon other algse between
whose
filaments
it
becomes
entangled,
furthermore
fixing
itself
by means
of
rhizoids which seem
to
be
able to grow out nearly
everywhere from the margin of the thallus (Fig. 344). The rhizoids
issue not only from the coherent tissue, but also from the reticular
part of the thallus (cp. the figures of SVEDELIUS,
1. c., p. 34, fig. 34).
A supposition expressed by SVEDELIUS and one to which
I am quite
willing to subscribe is that parts of the plant torn loose or such ones
becoming
free by the decomposition
or
dying away
of
the
net
are able just by means of these rhizoids to fix themselves and give
rise to new plants.
Martensia
Pavonia
(Fig.
345)
together
with
the
Australian
Martensia denticulata form a small, distinguished group within the
genus Martensia, both
species being by
J. AGARDH referred to his
subgenus
Mesotrema.
What
especially
characterizes -this group
is
the belts of coherent tissue and reticular tissue successively following
349
each other while in the other species of Martensia this arrangement
is not found at all or at any rate only slightly indicated.
According to SVEDELIUS the coherent tissue of the young frond
is formed by filaments congenitally connate
just as
in the case
of
the other
Delesseriacese.
Later on intercalary
cell-divisions
contri-
bute to the growth of the tissue. When the coherent tissue has reached
a
certain breadth the development
of the net
begins. Some large
cells, becoming the
basal
ones
of
the
net,
are
formed along the
margin and from each
of these a row of
cells grow up; these
cell
rows are mutually free with the
exception
of
the uppermost
cells
of the rows which
at both
sides
all
are connected to-
gether with those
of the neighbour
cell-rows.
From
these
connected
cells the next belt
of coherent tissue
originates (comp.
Fig.345).Thefiee
rows
of
cells are
running
nearly
parallel
to each
other;
their
cells
are soon divided by horizontal
walls
(lying
in
the plane
of
the
thallus),
the
cell-rows
herewith
being
transformed
into
lamellae.
In
this way
the
longitudinal
beams
of
the
net
are formed.
About the same time when
divi-
sion
of
the
cells
takes
place
in
the
longitudinal
rows
of
cells
the cross-beams
of the net begin to grow out.
In Martensia Pa-
vonia these are formed in such a way that a cell in the longitudinal
cell-row grows out unilaterally in the direction of the neighbour cell-
row (comp. the fig. 33 of SVEDELIUS). This outgrowth, being separated
from the mother
cell by a wall, soon reaches the opposite cell-row
and then grows together with it in a way very similar to that found
e. g.
in Dictyurus, Microdictyon etc.
In forming the cross-beams
in
this way Martensia Pavonia differs for instance from Martensia fra-
gilis in which two outgrowths issue oppositely from each
cell
; these
outgrowths meet those issued from the neighbour cell-rows half-way
and grow together conjointly.
Fig. 344. Martensia Pavonia
J. Ag.
Part
of the coherent
tissue with groups
of rhizoids
issued from the margin.
(About
80:1).
350
SVEDELIUS maintains that the cross-beams are given oif rather
regularly at nearly the same height, but this holds good only with
regard to the young tissue
; later on in the older tissue so many new
cross-beams
are formed
at various distance and height that
their
distribution
is quite irregular. Sometimes, but not always the
cells
of the cross-beams in the older net are divided so that these consist
of a few layers of
cells just as in the case of Martensia fragilis.
Fig. 345. Martensia Pavonia
J. Ag.
Part
of the
thallus.
(About
10:1).
Finally in the older net secondary longitudinal beams are formed
running
nearly
parallel
to
the
original
longitudinal
lamellae.
As a rule they protrude themselves freely (cp. Figs. 345,
346), but
it may happen that they reach another
similar
cell-row and grow
together with
it. These secondary longitudinal
cell -rows were not
found
in
the
material
examined by
SVEDELIUS,
but
SVEDELIUS
asserts that they are found
in Martensia flagelliformis with which
species
Martensia Pavonia therefore
agrees
in
this
respect.
Tetrasporangia
did
not
occur
in the specimens examined by
SVEDELIUS. They (Fig. 346) are formed in the oldernet, but
I have also
351
found them a few times in the coherent
tissue. They occur in small
sori
; later on these sori often merge into smaller groups. When they are
found
in the coherent
tissue the
sori, too, merge into rather large
groups. When the tetrasporangia are ripe they become free through
holes formed by the bursting of the covering cells
; the net gradually
dies away and is dissolved.
In this way the coherent part of thallus
becomes free and is able to give rise to new plants as mentioned above.
SVEDELIUS
has found male
plants
in the
material examined
by him.
The
antheridial stands
occur
upon the sides of the lamella in the net
as roundish, mostly definite
sori (com-
pare SVEDELIUS, I.e., p. 66, fig. 49); some-
times
it
happens
that
some
of
the
antheridial
groups
become
connected
through the
fertilization
of the
tissue
between them.
I have not found cystocarpic plants.
When the plant grows in shallow water
it
is rather robust, the thallus
is broad
\2f
and proportionally short. Sometimes
it
covers smaller algae e.
g. Hypnea, quite
densely,
forming
together with
these,
roundish
tufts.
In specimens from deep water on
the
other
hand
the
thallus
is
thin,
Y\%.
346.
elongated and narrow. The meshes
in
the net are large. The lamellae are thin,
and
proportionally
few
cross-beams
are found. Secondary longitudinal lamellae were also found in some
of the deep water specimens.
This species was found in shallow water in somewhat sheltered
localities
and
in
deep water
in
the more
open
sea down
to
a
depth
of
about
30
meters.
It
had tetrasporangia
and
antheri-
dial
stands
in
the
months
January
March.
St. Croix:
Lt. Princess, here
often washed
ashore;
near Buck
Island
(about
10 meters).
St. Jan:
In
the
sound
between
this
island
and
St.
Thomas
in
several
places.
Geogr. Distrib.: West
Indies.
Martensia
Pavonia
J. As.
Part
of
the
net
with
tetrasporangia.
i M.out
70:1).
352
Fam.
4. Bonnemaisoniacece.
Asparagopsis Mont.
1. Asparagopsis
taxifonnis
(Delile)
Collins
et Hervey.
COLLINS and HERVEY, Alg. Bermuda,
p.
117.
Asparagopsis Delilei Mont, in BARKER-WEBB
et BERTHELOT,
Hist. nat.
lies Canaries,
t.
3,
part.
2,
sectio
4.
1840, Addenda,
p. XIV.
J. AGARDH,
Spec.
Alg.
vol.
II,
p.
Ill,
p.
776;
Epicrisis,
p.
666.
KUTZING,
F.,
Spec.
Alg.,
p.
802;
Tab.
phycologicse,
vol.
XIV,
tab.
92.
ASKENASY,
E.,
For-
schungsreise
Gazelle, IV
Theil,
Bot.,
p.
40,
Taf.
IX,
fig.
9,
10.
Dasya Delilei Mont., in WEBB
et BERTHELOT,
Hist.
nat.
lies Canaries,
t. 3, part 2,
sect. 4, p. 166,
7,
pi. VIII,
fig.
6.
Fucus taxiformis De-
lile, Flore d'Egypte, p. 151,
pi.
57,
fig.
2.
C. AGARDH,
Spec.
Alg.,
p.
368.
Lictoria taxiformis
J.
Ag.,
In
historian!
Alg.
Symbol,
in
Linnaea.
vol.
XV,
1841,
p.
23.
I quite agree with
COLLINS and HERVEY
that the original speci-
fic name
of
this plant
ought
to
be
adopted
because MONTAGNE,!.C.
p.
166,
only
honoris
causa, replaced the spe-
cific name given
it by
DELILE and
called
it
A. Delilei.
The
plant
grows
in
tufts
formed
of
creeping
rhizome-like
terete stems from which the beautiful ostrich-feather-like erect shoots
Fig.
347. Asparagopsis taxiformis
(Delile)
Collins
et Harvey.
a, part
of the creeping basal stems with
nume-
rous
branchlets
and
rhizoids
in
their summits;
upon the upwards turned side of the stem young
erect
shoots,
b, end
of a branchlet with rhizoids.
(a, about 25:1,
b,
175:1).
arise.
The creeping stems
(Fig. 347 a)
are very irregularly ramified.
The branches consist of two kinds, either branches with continuous
growth or branchlets with definite growth and without ramification.
The branches grow out either to decumbent, creeping branches, con-
tributing in this way towards the ramification of the basal part, or
the thallus.
(About
250:1).
they bend upwards becoming erect shoots. The branchlets
are vigorously developed, conical in shape with a broad
base and a more
or
less acute summit
(cp.
Fig.
347).
They fix the plant to the substratum through numerous
recurved
rhizoids
breaking
out
from
their
summits.
These rhizoids
are
often rather
long,
cylindrical,
with
p.
348
transverse walls, and attach themselves to the substra-
Asparagop-
turn: stones,
shells, calcareous alg*
etc.
S
jnis ('oelile}
^ne erec* shoots reach a height of about 20 cm. They
Collins
et
are barren in their basal part
; richly pinnately ramified
sSSTof
in the
iipper Part -
The
thallus
increases by means
of an
apical
cell
from which segments are cut off by oblique walls in vari-
ous directions (Fig. 348). From these segments the cen-
tral
cells
originate and the
peri-
pheral
cells,
too,
which
through
numerous
divisions
are
divided
into
the epidermal
parenchyma-
tic
tissue.
The branches grow out at an
early stage
even
before the
seg-
ments are divided. They begin as
small
roundish
outgrowths
from
the segments, two from each.
Of
these outgrowths the
largest one
issues at the broadest
side
of the
oblique segment appearing earlier
than the
other,
smaller
one, and
this different stage of vigour and size
of each
pair
of branches
is kept
and
clearly
seen
later
on
also
in
the
older
parts
of the
plant.
Furthermore, besides this different
development, the two branches of
each pair
are not placed exactly
opposite to each other, but a little
^ part
of a branch showing the
ra _
obliquely
(cp.
Figs.
348,
349 a),
rnification,
the lowest branchlets
to
Tn tho fiillv Hpvplnnpd thallus
the
riSht
with
a
y ung
cystocarp.
In the fully developed
^ transverse section of a thin brand.
-
let.
(a, about 25:1;
b,
80:
1).
23
Fig.
349. Asparagopsis
taxiformi*
354
Fig. 350 Asparagopsis
taxiformis
(Delile)
Collins
et Hervey.
,
longitudinal
section and
6,
transverse section of
the
thallus
a, about 50:1;
6,
75:1).
this
form
of ramification takes
place
several times, the branches
of each
higher
order becoming
only
shorter and
less vigorously
developed.
Fig.
349 a
gives
a representation
of the
ramification.
A part
of a branch-system of a somewhat higher order
is here
fig-
ured in which the most vigorous branches of each pair are ramified
only, while the others are unbranched
; and the side-branches of the
ramified branches are all unbranched. The result of this ramification
is,
that
the
fully
developed
thallus
gets
a
beautiful
featherlike
appearance.
The
thin
branchlets
consist
of
three
rows
of
cells
without
any
central
cell
(Fig.
3496),
the
cells being alternately arranged
(cp. Fig. 351^1). On the other hand the thicker branches and the main
branches have
a well developed
central
axis
of
a rather
peculiar
appearance.
ASKENASY has given a short description of the anatomical con-
355
struction of the stem, but as this
is rather
brief.
I shall give a fur-
ther description together with some figures.
Upon a transverse section of the main stem in the neighbourhood
of the place where the pair of branches issue we find an arrangement
like that shown in Fig. 350 b. The central cell
is here very large, its
diameter reaching a length of about 180 u.
It is surrounded by a cir-
cular open space filled with sap, round which again follows the rather
thick, parenchymatous, peripheral tissue. On both sides of the central
cell, but not exactly op-
posite,
two
filaments
issue.
One of these fila-
ments
is
thicker
and
more vigorous than the
other and
both
extend
themselves
in the bran-
ches given
off
here the
more
vigorous
in
the
thickest, the other in the
thinnest of the two bran-
ches. From the first cell
of
these
ramifications,
the one
nearest
to the
central cell, thin hypha?-
like
filaments
issue
in
all
directions,
the
cells
in
this
way
becoming
stellately ramified. These
thin filaments run up and down
in the space within the
interior
wall of the
peripheral tissue
; they are rather irregularly, often sub-
dichotomically,
ramified.
The
peripheral
tissue
itself
consists
of
5
6
layers
of
cells
of roundish shape,
largest
in the interior, de-
creasing gradually towards the
periphery.
A longitudinal section (Fig. 350 a) shows that the
central
axis
consists
of very long
cells
about
1 500 |u long,
being
in the upper
part
cylindrical
(about 45
(a thick) and
in their lowest
part much
swollen, nearly globular.
It
is
from
this
globular part
that
the
branches
issue.
Of this plant only female ones were gathered. The procarps oc-
curred at the tip of short clavate
branchlets (Fig.
351^4)
growing
23*
B
Fig.
35J.
Asparagopsis taxiformis
(Delile)
Collins
et Hervey.
A,
part
of a branch with procarp.
(25:1);
B,
cystocarp
(about
8:1).
356
out
at the base
of the pinnate side-branches. A single almost ripe
cystocarp was found (3515);
it was
nearly spherical, placed term-
inally upon
a
short,
thick branch.
My
plants were
gathered
in
March; MUe VICKERS
has had
plants with cystocarps
from
Bar-
badoes
collected
in
July.
Antheridial stands
have
been
described by ASKENASY,
I.e.;
according to him the antheridia cover more
or
less completely the
summit
of short clavate branchlets.
This plant has been dredged a few times in deep water only, at
a depth of about 12 fathoms.
It was growing in a place where strong
currents prevail and was gathered with young
cystocarps
in
the
month
of March.
St. Jan:
In
the
sound
between
this
island
and
St. Thomas
off
Cruz Bay.
Geogr. Distrib.: West
Indies, Canary
Isles, Mediterranean Sea, Pa-
cific" Ocean.
IV.
Gigartinales.
Fam.
1. Gigartinacece.
Subfam.
1. Gigartineae.
Gigartina
Stackh.
1.
Grigartina
acicularis
(Wulf.) Lamour.
LAMOUROUX, Essai des Thalassiophytes, 1813, p.
48. AGARDH, J., Spec.
Alg., vol.
II,
p. 263; Epicr., p. 190. KUTZING, Spec. Alg., p. 749; Tab. Phycol.,
vol.
18,
tab.
1. HARVEY, W.
H., Phycol.
Brit.,
tab.
104.
Fucus
acicularis Wulf., Cryptogama
aquatica,
p.
63, No.
50.
TURNER,
Fuci,
tab.
126.
For more synonyms compare DE-TOM,
Sylloge
Alg.,
vol.
IV,
sect.
I,
p.
198.
This species has only been gathered once in shallow water and
in a sheltered place. The few specimens found were sterile.
St. Croix: The harbour
of Christianssted.
Geogr. Distrib.: Seems
to occur
in
all warmer
seas.
357
Subfam.
2. Tylocarpeae.
Gymnogongrus
Mart.
1. Gymnogongrus
tenuis
J. Ag.
J. AGARDH,
in
Act.
Holm.,
1849,
p.
88;
Spec.
Alg.,
vol.
II,
p.
319;
Epicr.,
p.
211.
Chondrus
tenuis J.Ag.
in KUTZING,
Spec.
Alg.,
p.
736;
KUTZING, Tab.
Phycol.,
vol.
17,
pi.
52.
The specimens form dense bushes upto
5
6 cms height. The
thallus is of a firm and cartilaginous consistency;
it is flat and repeat-
edly forked
(Fig.
352).
From a transverse
section
of
the
thallus
it appears that
it con-
sists of a parenchymatic
tissue, whose
cells
are
largest
in
the
middle
(about 4050
|a
lat.)
smaller outwards. The
cortical
layer
consists
of
small
cells
with
thick
walls
placed
in
rows forming together
a very firm
tissue.
It
is
surrounded
by
a
rather
thick
cuticle.
In some of the specimens, collected in March, cystocarps were
found forming proportionately
large,
flat, roundish-oval project ing-
discs on the one side of the thallus.
The plant is a littoral alga.
It was. growing on stone-quays etc.
together with Grateloupia,
Ulva
etc. near the surface of the sea in
places where the waves constantly dash the stones and where the
water was much
polluted.
St. Thomas: The harbour
of Charlotte Amalia.
Geogr. Distrib.: West
Indies, Mexico, La Guayra.
Fig.
352. Gymnogongrus
tenuis
J. Ag.
Part
of the
thallus.
(About
-h).
358
Subfam.
3. Kallymenieae.
Kallymenia
J. Ag.
1.
Kallymenia
peiiorata
J. Ag.
J. AGARDH, Bidrag
till FJorideernes Systematik,
p. 9;
Epicrisis,
p. 21H.
B0RGESEN,
F., Some new or
little known West
Indian
Floridese,
II,
p. 180.
A
few
specimens
of
this
plant,
first
described
from
Ceylon,
were dredged in the sea around St. Jan. As mentioned in my paper
quoted above
I have been able, through the kindness of Prof. SVE-
Fig.
353. Kallymenia perforata
J. Ag.
a,
transverse
section
of the
thallus.
b,
a
stellate
cell.
(About
150:1).
DELIUS in Upsala, to compare my plant with an authentic specimen
from Ceylon. From this comparison
I arrived at the conclusion that
both plants, as to their outer habit and anatomical structure, seem
to agree
perfectly.
The plant has an Ulva-\ike, flat thallus, perforated by numerous
roundish holes, smaller in the young thallus, larger in the older, this
receiving thereby a reticular appearance. The holes seem to originate
through
the
tissue in
certain
places becoming
absorbed.
At any
rate
I have several times in younger parts of the thallus found small,
roundish, rather well-marked
spots in which the
tissue was much
thinner than in the other part of the thallus, these thinner parts being
undoubtedly the beginning of the holes.
A transverse section of the thallus (cp. Fig. 353 a) shows that
this consists on both
sides
of a rather
loose and thin-walled
cell-
tissue and
of a cavity
in the middle through which filaments are
running
in
all
directions.
359
At the surface on both sides of the flat thallus we find a cortical
layer composed
af small roundish
cells
of somewhat variable
size.
Below this tissue a layer of large cells follows. These cells are of rather
variable shape, often with long
prolongations. The innermost
cells
facing the cavity in the interior of the thallus, have often several
prolongations becoming more or less regularly stellate of shape (Fig.
3536). From these cells longer nearly cylindrical cells or shorter oval
ones
forming
shorter
or
longer
chains
issue connecting
the
cell-
layers
of both
sides.
How far this plant
is rightly referred to the genus Kallymenia
seems
to me rather problematic.
Its anatomical
structure,
at any
rate,
is not much
like that found in the Fam. Gigartinacex, and it
shows much more likeness to that occurring in forms belonging to
the RkodymeniacedB,
e.
g. Chrysymenia,
to the
flat forms
of which
it bears a
close resemblance. Nevertheless until fructiferous organs
are
found
I
think
it
preferable
to
let
it
remain
in
the
genus
Kallymenia which according to SCHMITZ (in ENGLER u. PRANTL, Nat.
Pflanzenfam.
Teil
I, Abt.
2, 1897, p. 365) contains forms most prob-
ably belonging
to
several
different
genera.
The specimens were
all sterile; they were dredged only in deep
water (about 30 meters) in places where strong currents prevail and
found attached
to other
alga?,
stones
etc.
St. Jan.
In
the
sound
between
this
island
and
St. Thomas
near
Gr.
St. James, and near Maria
Bluff, Whistling Cay.
Geogr. Distrib.:
Ceylon, West
Indies.
Fam. 2. Rhodophyllidacece.
Subfam.
2. Cystoclonieae.
Catenella Grev.
1.
Catenella
Opuntia
(G.
et W.)
Grev.
GREVILLE,
R.
K.,
Algae
Britannicse,
1830,
p.
166.
pi.
17.
HARVEY,
Manual,
p.
51; Phycologia Britannica,
pi.
88. AGARDH,
J.,
Spec.
Alg.,
vol.
II,
p.
352;
Epicrisis,
p.
588.
Fucus Opuntia Good,
et Woodw., Observations
on the
Brit.
Fuci
in
Linn.
Trans.
Ill,
p.
219.
STACKHOUSE,
J.,
Nereis
Brit.,
p.
42.
TURNER,
Fuci,
pi.
107.
Catenella pinnata Harv., Nereis Bor.-Am.,
p.
201,
pi.
29 B.
This small plant was found a few times in lagoons growing upon
the roots of the mangroves to which it fixes itself by means of haptera
360
(Fig.
354). These
are,
as a
rule, developed from the narrowings of
the thallus and consist of a short stalk ending in a broad disc. As the
specific name indicates the shape
of the thallus reminds one very
much of that of Opuntia, being rather regularly narrowed and again
enlarged, giving
it a resemblance to a chain whose single joints are
elongated
elliptic. From
the
thickest
part
of the
joints, which
is
Fig. 354.
Catenella Opuntia
(G.
et W.)
Grev.
Parts
of
plants,
a, from below;
b, from
the
side.
(About
6:1).
found frequently somewhat above the middle
of the joint, one
or
commonly two opposite side-branches grow out, these sometimes be-
ing erect, and sometimes bending downwards in different directions
and fixed by haptera to the mangrove roots. By this way of growing
a felted cover about 2 cms high is produced round the roots.
From transverse and longitudinal sections of the thallus (com p.
OKAMURA, Icones, vol.1, pi. 39) it appears that the tissue in the middle
consists of several thick-walled filaments running the length of the
plant and composed of rather long, cylindrical cells. From these cells thin
filaments are given off in all directions towards the periphery, being
bi-or tripartited several times, forming a very lacunose tissue. Near the
periphery the filaments are much ramified, their cells becoming smaller
and densely packed, forming in this way a firm cortical layer.
361
All my specimens were sterile. Upon the whole this plant seems-
seldom to fruit, at any rate it is seldom found in a fruiting condition.
HARVEY GIBSON has given a description of fertile plants. Referring
for more detail to his paper*) I shall only mention here that according-
to him the tetraspores are formed in the cortical layer. They have
zonate division.
The antheridia and cystocarps occur often upon the same plant.
The antheridial stands
consist
of numerous small groups immersed
in the cortical tissue, and they are found upon small wrinkled
ra-
muli (compare also BUFFHAM**).
The cystocarps
are nearly
spherical bodies with a short
stalk
placed upon the erect branches, every articulation
bearing one
or
two of these small cystocarpic branchlets.
I shall not here enter into
a more
detailed
description
of the development and very peculiar
construction of the cystocarp, but only mention that the carpospores
are formed in great numbers in the interior and that the spores seem
to get free by rupture of the cortical layer as no carpostome is found.
This
is a
littoral alga found at the islands in sheltered places
only. Growing as it does in the shade of the mangroves it is able ta
grow even a little above the surface of the sea.
It
does
not
seem
to
be common
at
the
islands.
St.. Groix:
Chri-
stianssteds Lagoon;
Saltriver Lagoon.
St. Thomas: Bovoni Lagoon.
Geogr. Distrib.: Seems
to occur
in
nearly
all warmer
seas.
Agardhiella Schmitz.
1.
Agardhiella tenera
(J. Ag.) Schmitz.
SCHMITZ,
FR.,
System.
Uebers.
Gatt.
Florideen
(Flora,
1889,
vol.
72,.
p.
435);
in ENGLER
u. PRANTL, Nat.
Pflanzenf.,
Teil
I, Abt.
2,
p.
371.
Rhabdonia tenera
J. Ag., Spec.
A)g.,
p.
354;
Epicrisis,
p.
592.
OSTER-
HOUT, On the
life-history
of Rhabdonia tenera
J. Ag.
(Annals
of
Bot., voL
X,
1896).
Solieria chordalis
Harv., Nereis Bor.-Am.,
vol.
II,
p.
121,
tab.
23^1.
Rhabdonia Baileyi
Harv.
in KUTZING,
Tab.
Phycol.,
vol. XVI,
p.
26 r
pi.
74
c,
d.
*) HARVEY,
GIBSON,
R.
J.,
On
the
structure
and
development
of
the
cystocarps
of CatenellaOpuntia Grev.
(Journ.
Linn.
Soc.,
Bot.,
vol. XXIX,
London
1893).
**) BUFFHAM, T. H., On the reproductive
organs,
especially the antheridia,
of some
of the
Floridea?
(Journal
of the Quekett microscop.
Club,
vol.
III r
Ser.
II,
p.
5,
pi.
21,
figs. 1011).
362
The
life-history
of
this plant has been
studied very minutely
byjOsTERHOUT. The following short description is based partly upon
his
description, partly upon my own
observations.
Agardhiella grows
at the
islands
in more
sheltered
places
in
shallow water and likes localities with sandy or muddy bottom sprink-
led with stones. To these the plant
is fastened by means of a disc
from which often several erect stems arise. These are much branched
Fig. 355. Agardhiella tenera
(J.
Ag.) Schmitz.
a,
transverse section
of the
thallus.
b, longitudinal
section
of the
thallus.
(a, about 80:1;
b,
45; 1).
in all directions, the plant forming in this way small highly branched
bushes up
to about a foot high. When
growing
in shaded
places
their colour
is a clear rosy-red,
in strong
light on the other hand
they assume a more yellowish-brown tinge.
The summit
of the plant looks like several densely placed
fila-
ments. According to OSTERHOUT'S examination and as far as
I have
seen there
is nevertheless a central filament and
lateral filaments
extending from
it.
Transverse and longitudinal
sections
of the thallus
(Fig.
355)
show that
there
is
in the middle
a very
loose
tissue
consisting
of long much curved and bent
filaments, now and then
ramified
and running
between
each
other.
In
the
fully developed
thallus
this medullary
tissue
is
so
loose
that we may
rightly
say
that
there
is,
in
the
interior
of the
thallus,
a
cylindrical cavity
filled
with
sap through which the filaments
run.
The peripheral
tissue
is
firmer,
consisting
innermost
of
one
or
two
layers
of
large,
roundish-polygonal cells covered by a layer of small epidermal
cells.
363
The tetrasporangia, antheridia and cystocarps are found upon
separate
plants.
The tetrasporangia are developed in the peripheral tissue. The
mother-cells
of
the
sporangia become
enlarged,
filled with
proto-
plasma and getting a dark red colour. They are zonately divided.
The
antheridial
stands
occur
every-
where
upon
the
sur-
face of the male plants
forming smaller or larg-
er groups.
The procarps and
carpogonial
branches
are formed on the inner
side of the peripheral tis-
sue facing the cavity in
the
thallus.
We
will
therefore
begin
to
ex-
amine a section of this
tissue from the summit
of a female plant.
Fig.
356
shows
a
part
of
such a section;
the in-
nerside
of
it, which
is
facing the cavity of the
Fig
.
356
Agardhiella
tenera
( J. Ag.) Schmitz.
thallus,
is turned up-
Part
of the
tissue seen
from
the
innerside with
auxiliarv-cell branch and
carpogonial branches.
wards.
To
make
the
(About
250:1).
organs of reproduction
more
clearly
visible
I have
coloured
the
tissue
in
hsematoxylin.
In the middle of the figure we find a short branch composed of
rather robust
cells.
It
originates from
one
of the filaments found
on the innerside of the peripheral tissue, whose large
cells are seen
underneath. This branch
consists
at
first
of
a
smaller oblong
cell,
then follows a larger one having in this case an outgrowth on the
left
side. The next
cell
is especially coloured by the heematoxylin
and filled to a great extent with granular cell contents;
it has also
a thicker wall than the other
cells
of the branch. This
cell
is the
auxiliary cell.
It always bears three cells. In the figure two of them
only are visible, the third one
is lying underneath the auxiliary cell.
364
But in Figure 357 showing a similar branch
all three
cells are seen.
From these three
cells the pericarp
originates,
in
fig.
356 each
of
the two
cells seen have already produced a single
cell each.
Quite independently and separated from the auxiliary branch-
system
the carpogonial branches are developed. These are formed
in much greater number than the auxiliary branches. In the part of
the tissue shown in the Fig. 356 six are to be
seen. The carpogonial
branches are borne either from the large cells of the peripheral tissue
or
from the
filaments
found here.
It consists
of a variable number of
cells, about two to four
or sometimes five cells.
The trichogyne is long,
mostly
screw-formed
with a thickened sum-
mit; in penetrating the
peripheral tissue it be-
comes thinner.
In the
figure the trichogynes
of
the
carpogonial
branch to the
left and
those of the carpogon-
ial branches nearest to
the
right
of
the
auxiliary
branch
have
penetrated
the
peri-
pheral
tissue
to
become
fertilized.
After
the
fertilization
the
trichogyne gradually
dies away, but
at
the
same
time
the
con-
jugating tube begins to grow out from the carpogone. The grow-
ing-out of this tube is seen in the carpogonial branch found close above
the auxiliary branch in Fig. 356. Sometimes two or even three of those
conjugating tubes
are developed from the
carpogone.
These tubes
are mostly very thin and may reach a considerable length; they pro-
trude freely everywhere in the cavity of the thallus, until one of them
succeeds in reaching an auxiliary cell. Then the summit of the tube
becomes thicker and closely connected with it merging together with
it. This process seems always to take place at the basal end
of the
auxiliary
cell. Fig. 357 shows this stade of the fertilization; in this
ease the conjugating tube
is issued from a carpogonial branch just
Fig. 357. Agardhiella tenera
(J. Ag.) Schmitz.
The process
of
fertilization.
(About 350:1).
365
in the neighbourhood of the auxiliary branch, the conjugating tube
being by reason
of
this much
shorter and thicker than
usual.
After the
fusion with the conjugating tube the
auxiliary
cell
cuts off a small cell at its upper end, the central cell, and, after nume-
rous divisions this one gives
rise,
according
to OSTERHOUT, to the
gonimoblastic filaments from which the carpospores are developed.
At the same time the pericarp
is formed from the
sterile
cells.
The ripe cystocarp is a nearly spherical body lying imbedded in
the
cortical
layer and extending
far in to
the
medulla;
it
has
a
well developed
carpostome.
An interesting fact is mentioned by OSTERHOUT. The tetrasporic
plant is often provided with numerous short proliferations protruding
to
all
sides.
These
originate
from
germinated
tetrasporangia.
A whole tetrasporangium
is required
for each
proliferation.
The plant has been found with tetrasporangia, antheridia and
cystocarps in the months January to March.
It
is gathered in shal-
low water with the exception of a single specimen dredged in a depth
of about 30 meters.
The
plant
seems
to
be
rather common
at
the
islands.
St.
Croix:
Christianssteds Lagoon,
Saltriver, near Lt.
Princess.
St. Thomas:
In the
harbour
of Charlotte Amalia. St. Jan: Cruz Bay,
off America
Hill.
Geogr.
Distrib.:
Warmer
part
of
the
Atlantic
coast
of
North
America, West
Indies.
Subfam. 2.
Solierieae.
Rhabdonia Harv.
1. Rhabdonia ramosissima (Harv.)
J. Ag.
J. AGARDH,
Epicrisis,
p. 593;
Till Algernes Systematik,
4de
afd. VII,
Florideae,
p.
85.
Chrysymenia ramosissima Harv. Nereis Bor.-Am.,
p.
190,
pi. XXX B.
f.
dilatata
J.
Ag.,
1.
c.,
p.
85.
The specimens found belong to the above
form. The plant
is
fastened by means
of a small
disc. The
thallus
is
at
first nearly
terete,
but becomes
soon
compressed. The branches are given
off
from the edges and mostly regularly
opposite, now and then
also
alternating or
unilaterally.
In
vigorous
plants
this
ramification
is
repeated
several times.
The growing point
is composed
of nume-
rous
diverging
cell-filaments. Transverse and longitudinal
secsions
366
Fig. 358. Rhabdonia ramosissima (Harv.) J. Ag.
Part
of the
tissue showing a carpogonial and
an
auxiliary-cell branch. (About 350:1)
of
the
plantshow
that
it
is
constructed
in
a
way
similar
to
that
of
Agardhiella.
Also
the carpogonial
branch
and
the
branch
bearing the auxiliary
cell
are,
as
Fig.
358
shows,
formed in accordance with
those found in Agardhiella.
Both
are
formed
from
cells
of the
filaments
at
the
interior
wall
of
the
peripheral tissue. The car-
pogonial branch
consists
of three
cells; the thrichogyne
is long,
spirally bent and flattened
in the upper end. The auxiliary cell bears three sterile ones.
I have
not been able to follow
the development
of the
cystocarp
in
the
material brought home by me.
The tetrasporangia are formed in the peripheral tissue and are
zonately divided.
Plants
with
tetrasporangia and
cystocarps were
gathered
in
the month of March.
The plant was dredged in the more open sea in depth of about
10
15 fathoms. It was found rather sporadic and not in great number.
Some fragments of a nearly terete plant answering, as it seems,
to the description
of the forma Harveyana
3. Ag.,
1. c., were once
dredged.
St. Jan:
In several places
off Cruz Bay,
off America
Hill, off Anna-
berg.
Geogr. Distrib.: Key West.
Eucheuma
J. Ag.
1. Eucheuma
isiforine (Ag.)
J. Ag.
AGARDH,
J., Nya
alger
fran
Mexico
(Ofvers.
K.
Vet.-Akad.
Forh..
1847,
p.
16); Species Alg.,
vol.
II,
p.
627;
Epicr.,
p.
600.
HARVEY, Nereis
Bor.-Am.,
p. 118,
tab. 24.
Sphserococcus
isiformis
Ag.,
Spec.
Alg.,
p.
271.
KITZING,
Spec.
Alg.,
p.
777.
367
Fig. 359. Eucheuma
is iforme (Ag.)
J. Ag.
a, Part
of the
thallus
with tetrasporangia.
b,
transverse
section
of a branchlet with tetrasporangia.
(a, about
l
! /s:l; 6,70:1).
The specimens found were often more than a foot long. The thallus
is of a very cartilaginous consistency;
it is terete and, at any rate in
the young
specimens, oppositely or verticillately ramified. Some of
the branches grow out to main branches
like the mother branch;
most of them remain short as spiny branchlets.
The summit of the thallus consists of several filaments densely
packed together.
A transverse section shows that the thallus in the middle has a
small medullary tissue composed of slender, but thick-walled
cells.
This
is surrounded by a thick parenchymatic tissue whose cells are
roundish-polygonal with
rather thick walls. These
cells
are
largest
innermost growing gradually
smaller towards the
periphery.
It
is
surrounded by the epidermal layer composed of short radiating fila-
ments forming
2
3
layers
of
small,
oblong,
densely
placed
cells.
At the periphery a rather thick epidermis
is present.
A longitudinal section shows that the
cells of the medulla are
long, cylindrical. They are twisted between each other and now and
then ramified. The cells of the parenchymatic tissue have nearly the
same shape as when seen in transverse section.
Specimens with tetrasporangia and cystocarps are found. Both
kinds of organs
of
fructification occur in the spiny branchlets (Fig.
359 a),
the tetrasporangia also in the main stems.
The tetrasporangia occur
scattered
in the
cortical
layer
(Fig.
3596). This
is rather much developed. The cell-threads which form
it are longer and consist of more
cells than in the vegetative plant.
The tetrasporangia are formed as a side-branch from these filaments.
368
The
mother-cell
of
the
tetrasporangium
increases much
in
size,
especially in length, it becomes densely filled with granular contents
and
divided
zonately
in
four
spores.
The cystocarps are figured by HARVEY,
1. c. They form rather
large semiglobular bodies upon the branchlets with an opening in
the
upper
end.
This plant has been found
as well
in shallow
as
in deep
sea
down to a depth of about 30 meters. When growing in shallow water
the plant is very robust and does not reach any great height
; in deep
water
it becomes more slender and more than a foot high. When
found in shallow water
it occurred in more
protected places.
It was found with tetraspores and cystocarps in the month of
March.
St. Groix:
In the harbour
of Ghristianssted. St. Thomas: Near the
East end
of the
island;
near Thatch Cay
(leg.
Dr. Th. Mortensen).
St.
Jan: Cruz Bay, near Great
St. James.
Geogr. Distrib.:
Florida, West
Indies.
Genus incertaB
sedis.
Wurdemannia Harv.
1.
Wurdemannia
setacea
Harv.
HARVEY, W.
H., Nereis Bor.-Am., Part
II,
p. 246. KUTZING,
F., Tab.
Phycol.,
vol. XIX,
tab.
26.
The
plant
forms
low,
dense tufts or cushions upon
other
algae,
stones
etc.
It
consists of a filiform,
terete,
rather rigid thallus, ramified
very
irregularly
to
all
sides
and felted together (Fig. 360).
Some
of the branches grow
out to main branches, others
remain shorter or longer get-
ting a
spinelike appearance
with
their
acute
summits.
The
thallus
is
fixed
to
the
360. Wurdemannia setacea Harv.
substratum
bv
means
of
Part of the
thallus.
J
(About
2
/i).
small
discs
which
can
be
Fig.
369
formed
everywhere
from
the
surface
of
the
thallus. By means
of such discs the filaments of the plant, too, fix themselves mutu-
ally together
to
each
other. The connection
is
so
intimate that
mostly it
is impossible to decide from which of the two connected
filaments the hapteron
is given
off.
If we examine the apex
of the filaments
(Fig. 361 c)
it ap-
pears that the thallus increases by means of several filaments placed
Fig.
361. Wurdemannia selacea Harv.
a, transverse section
of the
thallus.
b, longitudinal section
of the
thallus.
c, apex of a filament,
(a, about 240:1;
b, about 130:1;
c, about 80:1).
close together and from which the different cell-tissues are formed.
Upon a transverse section
of the thallus
(Fig. 361 a) three
diffe-
rent layers are visible. In the middle a medullary tissue is present
composed
of smaller thick-walled, roundish polygonal cells; from
a longitudinal section
(Fig.
361 b)
it appears that these
cells are
rather long,
cylindrical, but
of variable length about 250
jn long
at their greatest
; the transverse walls are often somewhat oblique.
Then
follows
a parenchymatic
tissue, whose innermost
cells
are
larger gradually diminishing outwards. A transverse section shows
these
cells to be nearly circular
in
outline,
while
a longitudinal
section shows them to be actually oblong about 60
|u long. Finally,
the epidermal
tissue
consists
of
a
single layer
of
cells only;
the
cells are nearly as long as broad; when seen from above roundish
polygonal;
their diameter
is about
12
|^.
24
370
My material was
sterile.
The only known organs of reproduction are tetraspores ; these
have zonate
division and occur immersed
in the swollen ends
of
the
branchlets.
At the islands
I have dredged this plant in deep water only,
at depths
of about 20
30 meters.
St.
Jan:
In the sound between this island and St. Thomas
in seve-
ral
places.
St. Thomas:
In the sea to the west
of Water
Island.
Geogr. Distrib.: West
Indies.
V.
Rhodymeniales.
Fam.
1.
Sphceroccocacece.
Subfam.
1. Ceratodictyese.
Gelidiopsis Schmitz.
1.
Gelidiopsis
rigida
(Vahl) Weber-van Bosse.
WEBER-VAN BOSSE,
A., Note
sur deux algues de
1'Archipel Malaisien
(Recueil de travaux bot.
Neerl., Vol.
1,
p.
104,
1904). OKAMURA,
K., Icones
of Japanese
Algae,
vol.
II,
1912,
p.
34 and
p.
188,
pi.
59,
figs. 16.
Fucus
rigidus Vahl,
Beskrivelse
over
endeel
cryptog.
Planter
fra
St.
Croix
(Skrivter
af
Naturhistorie-Selskabet,
5.
Bd.,
2.
Hefte,
Kiobenhavn
1802,
p.
46).
Gelidium rigidum
(Vahl)
Grev., Alg.
Brit.,
p. LVII.
KUTZING,
Spec.
Alg.,
p.
766;
J. AGARDH,
Spec.
Alg.,
vol.
II,
p.
468;
Epicrisis,
p.
548.
Sphserococcus rigidus Ag.,
Spec.
Alg.,
p.
285;
Syst.,
p.
227.
Fucus
corneus
var.
spinseformis
Turn.,
Fuci,
IV,
p.
149.
Echinocaulon spinellum
Ktitz.,
Phyc.
gen.,
p.
40;
Spec.,
p. 762;
Tab.
phycol.,
vol.
18,
tab.
38.
Echinocaulon ramelliferum
Kiitz., Tab.
Phycol.,
vol.
18,
p.
14,
pi. 39.
Echinocaulon rigidum
Ktitz., Tab.
Phycol.,
vol.
18,
pi.
40.
Gelidiopsis rigida
is a common alga upon coral
reefs, stones,
shells
etc. upon which its decumbent base creeps; it forms more or
less dense
tufts upto a heigth
of about 10 cm or more.
It has
a
terete thallus of a very rigid, cartilaginous consistency and is rather
371
irregularly branched, some
of the branches being very regularly
pinnate
or bipinnate,
others bearing a few scattered
pinnules or
being quite barren.
Regarding the
anatomical
structure we
find
in the apex of
the plant an apical
cell
usually
rather broad with convex
sides,
sometimes
also more
conical
(Fig.
362 d, e). At the base
of this,
watch-glass-shaped
segments
are
cut
off. From
these
segments
Fig.
362.
Gelidiopsis rigida (Vahl) Weber-van Bosse.
a, summit
of young thallus covered with
hairs (about 50:1);
b, longitudinal
section
of medullary
cells (about 200:1);
c,
d,
apices of two filaments show-
ing
the
apical
cell
(about
500:1);
e,
transverse
section
of
the
thallus
(about
70:1).
short
filaments
originate,
diverging
in
all
directions
and
these
filaments
are
again
gradually, by
various
divisions, transformed
into a medullary tissue composed of thick-walled
cells all of nearly
the same size and an epidermal layer of densely placed small cells
(Fig. 362 e). From a longitudinal section
it appears that the
cells
of the medullary tissue are subcylindrical, about six times as long
as broad with more
or
less
oblique
walls
(Fig.
362 b).
When referring this plant to the genus Gelidiopsis Mme WEBER
was of the opinion that
it had no apical cell, OKAMURA (1. c., fig. 6)
being the
first who
observed
it.
Later on in the paper on "The
Rhodophycese
of
the
Percy
Sladen Trust Expedition" (Transact.
Linn. Soc., London 1914,
vol. XVI, Zoology,
p. 280) Mme WEBER
has corrected this mistake. In the above mentioned paper of OKA-
MURA good
figures
of
this
plant
are
found.
24*
372
In
the young parts of the
thallus long
unicellular
hairs
are
given
off from a great number
of the peripheral
cells forming a
dense
coating round the
filaments
(Fig.
362 a).
These
filaments
are
cylindrical
subclavate, being
a
little
thicker
in
the upper
end; they are about 200 ^ long and 6
7H broad. They have very
thin walls and
are
filled with protoplasma
in the upper end.
In
this
plant
tetrasporangia
are the
only known
organs
of
reproduction.
They
occur
in the upper
apices
of the
pinnules
which
become
swelled
and
conical
in
shape.
They
are
formed
here in great numbers in the peripheral tissue. The tetrasporangia
are
oblong, rather small, about 50
H long and 27 H
broad; they
are
cruciately divided.
In a recently published
list
of alga? from Bermuda, HOWE*)
has
replaced
this
plant
in
the genus Gelidium, and he bases his
opinion on the fact that Gelidium cartilagineum, which in several
respects shows likeness to the present species,
is allowed to remain
in the genus. As pointed out by Mme WEBER,
it
is especially the
non-existence
of the hyphse in the middle
of the thallus and the
great resemblance of the stichidia of this genus to those
of other
species
of
Gelidiopsis which makes
it most natural
to
place our
plant in the genus
Gelidiopsis.
Tetrasporangia were found in specimens gathered in the months
of January and February.
This
plant
has
originally
been
described
upon
specimens
from St. Croix which VAHL received from Rector WEST, and these
specimens
are
still in the Botanical Museum, Copenhagen.
It
is
a
very common
species
at
this
island, growing upon
coral reefs etc. in shallow water. At St. Thomas and
St. Jan
I
have
not
gathered
it
with
the
exception
of
quite
a
small
fragment
dredged
in
the
sea near
the
east end of the first men-
tioned
island.
Geogr.
Distrib.
: Seems
to occur
in
all warm
seas.
Subfam.
2.
Gracilarieae.
Gracilaria
J. Ag.
I
regret
to
say
that,
in the determination
of
several of the
species
of
this
polymorphic
genus,
I
have
not always
arrived
*)
In N. L. BRITTON, Flora
of Bermuda, New York
1918,
p. 514.
373
at a
definite conclusion, but to
attain this
result a monographic
examination
of
a
rich
material
af a
large number
of
species
is
necessary in order to determine how the plants vary under different
conditions.
How useful the examination of a large number of specimens
is,
COLLINS
and
HERVEY,
in
their work: "The Algae of Bermuda",
have shown, when they had the opportunity of examining a large
collection
of specimens which had previously been referred to the
three species Gr. Wrightii,
Poitei and
cornea. They arrived at the
conclusion
that they
,,can
find no
line
of demarcation between
the
three
species
mentioned". They therefore
refer
all
of them
to one and the same
species:
Gr. Wrightii.
Some of the ten species recorded in the following list have been
recorded
from the
islands
by
former
investigators.
Of
several
of these
species
I have found only very few specimens
or such
about
which
I
feel
a
great doubt. This
applies
for instance to
what
is
called
Gr. compressa.
I
greatly doubt whether
the
few
specimens
I
have
referred
to
this
species
really
belong
to
the
European
species
and
it
is
the same
in the case
of some
dried
specimens
from
St.
Croix
determined by
J. AGARDH and kept
in the Botanical Museum, Copenhagen.
1.
Gracilaria
confervoides
(L.) Grev.
GREVILLE,
R.
K.,
Alg.
Brit.,
p.
123. HARVEY,
Phycol.
Brit.,
pi.
65.
J. AGARDH, Spec.
Alg.,
vol.
II,
p.
587,
Epicr.
p.
413. THURET
et BORNET,
fitudes phycologiques,
p.
80,
pi. XL.
For more references see DE TONI, Sylloge Alg., vol. IV, Sect.
II, p. 431.
The specimens referred to
this species have a tissue
of very
large
cells
in the middle
of the
thallus,
often more than
1 mm
in diameter. The walls
of the
cells
are very
thin.
This
tissue
is
surrounded by a cortical layer one or two
cells thick. When dry,
the thallus
quite
collapses.
Plants with
cystocarps were gathered
in
the month
of
Ja-
nuary.
This
species occurs in shallow water and
in sheltered
places.
It
often grows
in
localities with
a sandy bottom sprinkled with
stones
to which the
alga
is
attached.
374
St. Croix:
Christianssted's harbour and
lagoon;
Lt.
Princess,
Green
Cay;
Longford.
Geogr.
Distrib.: Warmer Atlantic coast
of Europe, Morocco, Medi-
terranean
Sea, West
Indies, Cape, The Philippine
Islands
etc.
2.
Gracilaria
ferox
J. Ag.
AGARDH,
J.,
Spec.
Alg.,
vol.
II.
p.
592:
Epicr.,
p.
414.
A few not very typical specimens may,
I think, be referred
to
this
species. The
ramification and whole habit
of this
plant
shows some
likeness
to
Gr.
cervicornis, but
this
last
species has
a compressed
thallus. The branches are subdichotomously rami-
fied, the ramuli
short with
acute apex,
in the upper part of the
thallus
often
aculeate.
From a transverse section
of the thallus
it appears that the
cells
in
the
middle
are
large,
growing
smaller
outwards. They
have thin walls. The cortical layer is thin, one to two layers thick.
The
plant was once gathered on rocks near the
shore
in
a
rather exposed place, and once in the open sea at a depth of about
5 fathoms. According to
J. AGARDH
it has previously been found
at
St. Croix, and in the Botanical Museum, Copenhagen, a speci-
men
collected
at
this island by 0RSTED,
is
present.
St. Croix: White Bay,
off Frederikssted.
Geogr. Distrib.: West
Indies, Pernambucco.
3.
Gracilaria
coinpressa
(Ag.) Grev.
GREVILLE,
R.
K.,
Algae
Brit.,
1830,
p.
125.
HARVEY,
Phycol.
Brit.,
pi. 205.
J. AGARDH, Spec.
Alg.,
vol. II,
p. 593;
Epicr.,
p. 417.
Sphserococcus
compressus Ag., Spec. Alg., p. 308; System., p. 233. KUT-
ZING,
Fr.,
Spec,
Alg.,
p.
774; Tab.
Phycol.,
vol.
18,
pi.
78.
Comp.
for more synonyms DE-TONI,
Sylloge
Alg.,
vol. IV,
Sect.
II,
p.
438.
Only a few not very typical specimens may,
I
think, be
re-
ferred to this
species. Compared with Gracilaria confervoides they
especially
differ
on
account
of
their somewhat
thicker
thallus
and of the smaller cells in the interior of the filaments, their dia-
meter reaching only a length of about 300 K The cells have thin
walls. The cortical layer is thin, composed only of one or two layers
of
cells.
The
thallus
is
of
a
soft
consistence
and
collapses
in
drying.
According
to
J. AGARDH
(1. c.)
this
species
has been
found
375
at
St. Thomas and
in the Herbarium
of the Botanical Museum,
Copenhagen,
some
specimens,
determined
by
J.
AGARDH,
are
kept; they are collected by 0RSTED near Christianssted at a depth
of about
5 meters.
St. Croix: Coakley Bay.
Geogr. Distrb.
:
The
warmer
Altantic
coast
of
Europe,
Mediter-
ranean Sea, West
Indies,
Mexico.
4.
Gracilaria
caudata
J. Ag.
AGARDH,
J.,
Spec.
Alg.,
vol.
II,
p.
598;
Epicrisis,
p.
420.
The
specimens
referred
to
this
species
are, when dry, of a
corneous-cartilaginous
consistence. The main
branches
are
rami-
fied on
all
sides, upwards with shorter ramuli, the upper ends of
the branches being
bare.
From
a
transverse
section
the
cells
in
the
interior
of
the
filaments
are seen to be nearly
of the same
size
as those in Gr.
compressa,
their diameter reaching a length
of about 300
|a. But
their walls
are
thicker, and
the
cells
decrease more evenly out-
wards
and
pass
evenly
into the rather
thick
cortical layer
(Fig.
363).
As
I
have had no authentic
speci-
mens
at my disposal
I do not feel con-
vinced that my determination is right. In
referring my specimens
to
this
species
I
rely
on the
cartilaginous
consistence
of
the
thallus,
only slightly collapsed when
dry, and upon the anatomical structure.
Tetrasporic
plants were found in the
month
of February.
It
occurs
in
shallow water
in more
sheltered
places and
in
the open
sea
at
a depth
of about
10 meters.
St. Croix:
The harbour of Christianssted
and
Christianssted's
Lagoon,
Green Cay,
off Frederikssted. According
to
J. AGARDH
this species has previously been found
at
St.
Croix.
Geogr. Distrib.
: West
Indies, Mexico.
5.
Gracilaria
cylindrica nov. spec.
Gracilaria
Blodgetti
Borgs., Some new
or
little known West
Indian
Florideae
(Bot.
Tidsskrift,
vol.
30,
1909,
p.
18).
Fig.
363. Gracilaria
caudata
J. Ag.
Part
of a transverse
section (About
60:1).
376
Frons usque ad 22 cm longa,
e
callo
parvo,
discoideo
adsur-
gens,
caule
ad basin
tenuiori, mox
crassiori,
terete,
cylindrico,
ca.
I
1
/*
2 mm
crasso,
carnoso,
exsiccatione
collapse.
Kami
sparsi,
irregulariter
undique
orti, ad
basin
tenuiores,
celeriter
cras-
siores,
teretes,
cylindrici,
apice
late
rotundati.
Kami spe
simplices,
inter-
dum
ramosi,
ramulos parvos
in
superi-
ori parte
gerentes.
Tetrasporangia sparsa,
in cortice im-
mersa.
Cystocarpia
verrucosa in super-
ficie
plantae
sparsa.
After renewed examination and after
having
seen
a
specimen
of
Gracilaria
Blodgettii Harv.
it
is evident to me that
the
plant,
to
which
I
previously have
given
this
name,
cannot be
referred to
this
species, but must be regarded
as
a
new species for which
I propose the name
Gr.
cylindrica^
referring to the nearly cy-
lindrical
thallus, which
is only interrup-
ted by the narrowings
at the base of the
branches
(Fig.
364).
The plant reaches a height of about
22
cm.
It
is fastened to the substratum
by
means
of
a
small
disc.
The main
stem, being quite thin at
its
outgrowth
from
the
disc,
soon reaches the normal
thickness
of
the
thallus, about
I
1
/*
2
mm and
this thickness it keeps through-
out. The branches are issued on
all sides.
The ramification
is rather irregular with
shorter
or
longer
distance
between
the
branches.
These
are
altogether
a
replica
of
the
main
stem.
At
their
outgrowth
from
this
they
are
quite
thin,
but
rapidly obtain the normal
size
of
the
thallus
keeping
this
through
their
whole
length
(often
more
than
10 cm)
to
their obtuse
apex.
The branches
are
mostly
unbranched,
but
now
and
then
they
issue
a
Fig.
364.
Gracilaria
cylindrica nov.
spec.
Habit of a plant.
(About
4
/6 natural
size).
377
few branches
of quite
the
same shape
as
their own; sometimes
it may happen
that
such a branch
is given
off from the blunt
apex
of the mother branch.
The
plant
has
a
fine,
clear-rose
colour;
it
is somewhat dia-
phanous,
of
a
fleshy
succulent
consistency. When dry it collapses
completely, and it adheres mostly
very well
to the paper. A trans-
verse
section
(Fig.
365
c) shows
that
the
greater
part
of
the
tissue consists
of
large,
transpa-
rent
and thin-walled
cells;
out-
wards
these become smaller and
they
are surrounded by
a
corti-
cal layer consisting of one or two
layers
of rather small, thick -wal-
led
cells.
Seen from the surface
the
cortical
cells
are
irregularly
polygonal
(Fig. 3655).
In the tetrasporic plant the
tetrasporangia
occur
scattered
or
in
small
irregular groups
in
the
cortical layer
(Figs. 365 B, C). The tetrasporangia are round-
ish of shape, their diameter reaching a length
of about 40
JLI.
The female plant bears the warty, dark-red cystocarps
scat-
tered over the
surface.
The plant does not seem to approach any known Gracilaria.
From
Gracilaria Blodgetti it differs especially by the scarcer rami-
fication and the obtuse
apices
of the branches.
The plant was found with tetraspores and cystocarps in the
month
of March.
It was
dredged
in
deep
water
about 1015
fathoms.
The
Callithamnion
cordatum
is
a common
and
characteri-
stic epiphyte upon
this
Gracilaria.
St. Jan.: Found
in many places in the sound between this island and
St. Thomas; and
in
the sea to the north
of America
Hill.
Fig.
365.
Gracilaria cylindrica
nov.
spec.
A, transverse
section
of the
thal-
lus (about
8:1); B, surface
of
the
thallus with tetraspores;
C,
trans-
verse
section
of
epidermal
layer
with
tetraspores.
(B and C about
80:1).
378
6.
Gracilaria usneoides
(Mert.)
J. Ag.
J. AGARDH,
Spec.
Alg.,
vol.
II,
p.
595;
Epicrisis,
p.
415.
Fucus
usneoides Mert.
mscr.
Sphaerococcus
usneoides Ag.,
Spec.
Alg.,
p.
333.
This
species
has,
according
to
J. AGARDH,
been
found
at
St. Croix by ORSTED and in the Botanical Museum, Copenhagen,
some fragments of 0RSTED's plant are kept. These seem to show
some likeness to Gr. Wrightii, but they are more densely ramified
and the thallus
collapses when
it
is
dry.
Near Buck
Island
at
St. Croix
I have
dredged a few spec-
imens at a depth of about 5 fathoms which perhaps are referable
to
this
species: they show much
likeness to
Gracilaria
Wrightii,
but the
thallus
is
softer,
the
cells have
thinner
walls and they
collapse therefore when
dry.
Geogr.
Distrib.:
Brazil, West
Indies.
7.
Gracilaria Wrightii (Turn.)
J. Ag., emend.
Collins
et Herv.
COLLINS and HERVEY,
Algee
of Bermuda,
1917,
p.
109.
J. AGARDH,
Spec.
Alg.,
vol.
II,
p.
599
including
Gr.
Poitei
(Lam.)
J. AGARDH,
ibid,
p. 596 and
Gr.
cornea
J. Agardh,
ibid.,
p.
598.
The specimens
referred
to
this
species
are
all
coarse,
thick
plants
of
cartilaginous
consistence. They
are ramified very
irre-
gularly in every direction.
A
transverse
section
of
the
thallus
shows
that
it
consists
of a parenchymatic tissue of roundish, not very large cells, largest
in
the
middle
(about
180 H
broad)
decreasing
evenly
towards
the
periphery. The walls
of the
cells
are rather thick and often
undulated, especially in the case of the small
cells found between
the
larger
ones. Towards the periphery the
cells
decrease, being
about 20
30
(^ thick. A longitudinal
section, on the other hand,
shows that the cells are rather long, about 170
M, and have thick
and
sinuated
walls. The
cortical layer
consists
of short
dichoto-
mously
ramified
filaments composed
of
small
oval
cells;
at the
periphery a rather thick
cuticula
is found.
Specimens with tetrasporangia occurred in January and February.
The plant was found in shallow water in rather protected places.
St. Croix: White Bay, Lime Tree Bay. Some old specimens from the
island are kept
in the Herbarium
of the Botanical Museum, Copenhagen.
Geogr.
Distrib.: West
Indies, Red
Sea.
379
8.
Gracilaria
lacinulata
(Vahl).
Fucus
lacinulatus
Vahl,
Endeel kryptogamiske
Planter
fra
St.
Croix
(1799)
in Skrivter af Naturhistorie-Selskabet,
5.
Bd.,
2.
Hefte, Kiobenhavn
1802.
Gracilaria
multipartita
(Clem.)
J.
Ag.,
Alg.
Mediterr.,
1842,
p.
151;
Spec.
Alg.,
vol.
II,
p.
600;
Epicr.,
p.
423. HARVEY, Phycol.
Brit.,
pi. XV;
Nereis Bor.-Am.,
p.
107.
Sphserococcus
multipartitus Ag.,
Spec.
Alg.,
p.
247.
Fucus multipartitus Clemente, Ensajo, Madrid
1807,
p. 311 (non
vidi).
For more synonyms compare DE-TONI, Sylloge Alg., vol.
IV, Sect.
II,
p. 447.
We are obliged,
I think, to take up VAHL'S name for this plant.
His description is clear and striking and cannot be misunderstood,
even
if
the
specimens, upon which
he
founded
his
description,
cannot
be
identified
with
certainty
at any
rate
at the
present
moment.
This
is
of
course a regrettable drawback.
There
is in
the
Herbarium
of
the
Botanical Museum,
Copenhagen,
several
old
specimens
(called
Fucus
lacinulatus)
from
the
Danish
islands which surely have been
seen
by
VAHL,
but
none
of
these bear
his handwriting.
And that the specific name
of VAHL has been used for this
plant
is
shown,
too,
by the
careful
drawing
of
this
plant
reproduced here
(Fig.
366).
It
is
found
in
a book
containing
drawings
of several
algae
origi-
nating
from
Professor
FR.
WEBER
in
Kiel and
later
pre-
sented
to
the
Botanical
Lib-
rary,
Copenhagen by his royal
Highness
Prince CHRISTIAN.
Among the rather few spec-
imens,
which
I
have
gathered ^
myself,
forms
are found which O'
approach
partly
to
the
var.
Nr. 366. Gracilaria lacinulata (Vahl).
granatea (Turn.) J. Ag. (== Fucus
Compare the
text.
380
granateus Turner, Fuel, pi. 215), and
partly to the var. seruginosa
(Turn.)
J.
Ag. (= Fucus
aeruginosus
Turner,
Fuel,
pi.
147;
Besides
I have
some few specimens
approaching the
var.
poly-
carpa
(Grev.)
J.
Ag.
and
some
others most
likely
referable
to
the
var. angustissima Harv. These
last mentioned specimens
are
quite
terete
at
their base, but
in the upper
part
the
thallus
is
a little flattened being at the same time more or less bi-trifurcate.
Some
of these specimens were lying loose upon the bottom.
Gracilaria lacinulata occurs
in shallow water near the
shore,
partly in
sheltered
places,
partly
in more
exposed.
St. Croix: Longford, Christianssted's harbour, White Bay, Salt River,
Buck
Island.
Geogr.
Distrib.: Warmer
Atlantic
coast
of
Europe
and
America,
Mediterranean
Sea.
9.
Gracilaria deutata
J. Ag.
AGARDH,
J.,
Spec.
Alg.,
vol.
II,
p. 603;
Epicr.,
p. 424.
Sphcerococcus
oligacanthus
Kiitz.,
Tab.
Phycol.,
vol.
XVIII,
pi.
87.
Sphcerococcus rangiferinus
Kiitz.,
ibd.
pi.
86.
The
specimens
found
seem
to
agree
very
well
with
J.
AGARDH'S description. They have a thicker, more firm and cartila-
ginous
thallus
than
that
of
Gracilaria
lacinulata. The
thallus
is
several
times
bi-tripartite,
in
the upper end
flabellate. Along
the margin the specimens are more or less dentate. Some
of the
specimens lack the dents. These bear a close resemblance to some
specimens
in my
collection from
Jamaica,
gathered some years
ago at this island by Mr. 0. HANSEN and determined by the late
Major REINBOLD to be a form intermediate to the var. polycarpa
of
Gr.
lacinulata.
Transverse sections
of the thallus show that the
cells in the
present
plant
are much
smaller than
those
of
Gr.
lacinulata,
about 200
ij.
lat. The
cells become smaller outwards and are sur-
rounded by the
cortical
layer which
consists
of
a few layers of
cells,
oval
of shape.
The Fucus denticulatus of VAHL (in Skrivter af Naturhistorie-
Selskabet, 5te Bind,
2.
Hefte,
p. 45)
is most probably this species.
But
as
his
diagnosis
is
rather short and
as
I have seen no spec-
imens
from
VAHL'S
time,
I do not think
it right
to reestablish
his
specific name.
381
Plants with tetraspores were found in the month of February.
It has been gathered in shallow water near the shore in rather
exposed
places.
St. Croix: White Bay, Long Reef,
Lt.
Princess.
Geogr. Distrib.: West
Indies.
10.
Gracilaria
cervicornis (Turner)
J. Ag.
AGARDH,
J.,
Spec.
Alg.,
vol.
II,
p. 604;
Epicr.,
p.
425.
Fucus
cervicornis Turner,
Fuci,
pi.
121.
For more synonyms comp. DE-TONI,
SyJloge,
vol. IV,
Sect. II,
p. 452.
I
have not myself gathered
this
species
at the
islands, but
according to
J. AGARDH
it has previously been found at St. Croix.
And some
old specimens from
St.
Croix
are kept in the Herba-
rium
of the
Botanical Museum, Copenhagen. Some
of these
are
most probably collected by Rector WEST and sent to VAHL; but
being without
his
signature,
this
question cannot be
settled.
It seems to me that the description of Fucus versicolor given
by VAHL
in the year
1802
in
,,Skrivter
fra
Naturh.-Selskabet",
vol.
5, part 2, p. 44 on the whole answers to this species, but when
the ,,dentibus" are said to be "obtusissimis" it does not correspond
with
this
plant.
Geogr. Distrib.: West
Indies, Mexico,
Brazil.
Subfam.
3. Hypneeae.
Hypnea Lamouroux.
COLLINS and HERVEY
point out
in the "Algae
of Bermuda",
p.
112
13
that the
species
of Hypnea
are
generally
so
poorly
defined that any exact determination
is mostly excluded.
The
representatives
of
the
genus Hypnea seem
to
be very
variable plants, varying much according to their different growing
places. Several of the species described are most probably nothing
else but forms
of the same
plant.
1. Hypnea musciformis (Wulf.) Lamour.
LAMOUROUX,
Essai
Thalassioph.,
p.
43.
KUTZING,
Fr.,
Spec.
Alg.,
p.
758; Tab. PhycoL,
vol.
18,
tab.
19.
J. Agardh, Spec.
Alg.,
vol.
II,
p.
442;
Epicr.,
p. 561.
Fucus musciformis Wulf.
in Jacquin, Collectanea,
III,
p.
154,
tab.
14,
fig.
3
(non
vidi). ESPER,
Icones
Fuc.,
tab.
93. TURNER,
Fuci,
tab.
127.
For more synonyms compare DE-TONI, Sylloge Alg.,
vol. IV.
Sect.
II,
p. 472.
382
This
is
a common
species
along
the
shores
of
the
islands.
It occurs in shallow water and mostly in more
sheltered
places,
but
it
is
also
found
in somewhat
exposed
localities.
In
the
last
mentioned
places
where
the
light,
too,
was
strong
some specimens were gathered which
were
covered
quite
densely with
long,
unicellular,
hyaline
hairs.
These hairs serve most probably as
a
protection
against
strong
light*)
being present
in
so many
littoral
algae and non existing or less deve-
loped
in
those
from
deep water.
That the
hairs, on the other hand,
also may
serve as absorbing organs
of nutriments,
is very
likely**).
Hypnea musciformis
is often an
epiphyte
upon
larger
algse
and
occurs commonly entangled among
other
algse
to which
it
fixes
itself
by means
of the
tendrils.
Specimens with
tetrasporangia
were found in the month of February.
St. Croix: Christianssted's harbour,
Christianssted's
Lagoon,
Lt.
Princess,
White
Bay,
Casavagarden
etc.
St. Tho-
mas: Store Nordsidebugt. St. Jan:
Coral
Fig.
367. Hypnea cornuta
Bay, Cruz Bay.
(Lamour.)
J. Ag.
Geogr.
Distrib.
:
Seems
to
occur
Part
of a plant. (About
3:1).
in
all warmer
seas>
2.
Hypnea
cornuta (Lamour.)
J. Ag.
J. AGARDH,
Spec.
Alg.,
vol.
II,
p.
449;
Epicr.
p.
563.
Gigartina cornuta Lamour.
mscr.
Chondroclonium cornutum
Ktitz.,
Spec.
Alg.,
p.
741.
*)
Vide BERTHOLD,
G.,
Beitrage
zur
Morphologie und
Physiologie der
Meeresalgen.
Pringsh.
Jahrb.
f.
wiss.
Bot., Bd.
13, 1882
p.
675.
"*)
ROSENVINGE,
L. KOLDERUP: Remarks on the hyaline unicellular hairs
of the Floridese
(Biol. Arbejder tilegnede BUG. WARMING, K0benhavn 1911).
383
The
plant
(Fig.
367)
is
characterized by the
small,
stellate,
spiny branchlets found
scattered upon the
filaments. They have
35 rays and
are
peltately fixed
to the
branches.
Tendrils
are
now and
then
present,
but not upon
all
specimens. The
plant
forms rather large, richly ramified bushes up to about 20 cm high.
A transverse section (Fig. 368)
of
the
thallus shows rather large
cells
in
the
middle,
smaller
to-
wards the periphery. The
cortical
layer consists
of
a
single layer of
cells
which
have
a
very
thick
cuticula
often
25
-30
|a
thick. A
longitudinal section shows that the
cells
in
the
middle
are
about
3
4 times
longer than
broad.
The Acrodwetium Hypnese des-
cribed on page 51 of this volume
is
found
upon
this
plant
in whose
thick
cuticula
its
basal
part
is
immersed.
This species has been found a few times
in
sheltered
places
in shallow water.
Fig.
368. Hypnea cornuta
(Lamour.)
J. Ag.
Transverse section
of the
thallus.
(About 100:1).
St. Thomas:
in
the harbour
of
Charlotte Amalia;
St. Croix:
near
Christianssted. ORSTED has gathered
it as
St. Thomas.
Geogr.
Distrib.: West
Indies,
Guinea, Japan
etc
3.
Hypnea
cervicornis
J. Ag.
J. AGARDH,
Spec.
Alg.,
vol.
II,
p. 451;
Epicrisis,
p. 546.
Hypnea spinella
Kiitz.,
Tab.
Phycolog.,
vol.
18,
tab. 26.
The specimens
referred
to
this
species form roundish bushes
composed of numerous, much branched filaments. No main bran-
ches
are
present,
all the branches being of nearly the same
size
and
mostly
rather
thin. The
ramification
is very
irregular,
the
branchlets
longer
or
shorter with
acute
apices.
Frequently
the
upper ends
of the filaments
get an
antler-like appearance being
often curved and
their
branchlets
decreasing
in
length towards
the
top.
Some
of my specimens might
perhaps
quite
as
well be
re-
ferred to Hypnea divaricata Grev.
of which some specimens from
384
St.
Croix and
St. Thomas,
collected by 0RSTED and determined
by
J. AGARDH,
are kept in the Herbarium
of the Botanical Mu-
seum, Copenhagen.
I have specimens which
are
quite
identical
with these. They seem to be like a more
densely branched form
of the present
one.
It seems to me very likely that the specimens
I have referred
to
this
species
are only forms from more
protected
places, and
those
referred
to
the
following
species, Hypnea spinella, nothing
else but forms from more exposed
places.
This species occurs in more protected places in shallow water,
but
it has also been dredged in deep sea at a depth
of about 30
meters.
It was found with tetrasporangia and cystocarps in the
months
of February and March.
It
is a common
species along the shores
of the
islands.
Geogr.
Distrib.: Seems
to occur
in most warmer
seas.
4.
Hypnea
spinella (Ag.)
Ktitz.
KtfTZiNG, Spec.
Alg.,
p.
759.
J. AGARDH,
Spec.
Alg.,
vol.
II,
p.
453;
Epicrisis,
p. 565.
Sphserococcus
spinellus Ag.,
Spec.
Alg.,
p.
323; Systema,
p.
237.
This plant forms small compact
tufts upon rocks.
The plant
is very irregu-
larly ramified
(Fig.
369);
the
branches
are
issued
in
all
di-
rections,
in
some
cases
with
larger distance between them,
in others several branches are
crowded together. Some of the
branches
grow
out
to
main
filaments,
most
of them
be-
come
small,
short,
spinelike
branchlets
of variable length.
These much branched
fil-
aments
are
felted
between
each others and
further often
anastomosing
to
each
others
Fig.
369. Hypnea spinella (Ag.)
Ktitz.
by means of rhizoids breaking
Part
of
a
plant
with
anastomosing
out everywhere from the thai-
branches and
fertile parts with
tetra-
sporangia (about
10:1).
lus
(Fig.
369).
385
The tetrasporangia are formed in the branchlets. The fertile part
of these
is thicker than the sterile one. The quite short branchlets
become
fertile
in
their
whole
length,
the longer in
their
upper
end; sometimes
a
fertile zone
is found
in the middle
part
of
a
branch
(Fig.
369).
The
plant grows
in
shallow water near the
shore
in some-
what exposed
places where the waves often dash the rocks con-
stantly.
It seems to me rather probable
that
this
plant
is only
but
a
dwarfish
form
of
the
preceding
species
adapted
to
the
conditions
of
life
of the more exposed
localities.
The
plant
has been
found
with tetraspores
in
the months
of December and January and with cystocarps
in the month
of
February.
St.
Croix: White Bay;
St. Thomas:
In
several
places
near
Char-
lotte Amalia.
St. Jan: Cruz Bay.
Geogr.
Distrib.: West
Indies.
Fam. 2. Rhodymeniacece.
Subfam.
1. Gloiocladieae.
Gloiocladia
J. Ag.
1.
Crloiocladia
spec.
Only a single
sterile plant has been found.
It forms a small
roundish
tuft,
about
3 cm high and
has, when dry,
a
beautiful
rosy
colour. The
thallus
is
flat,
repeatedly forked,
its
divisions
being about 3 mm broad;
it seems to be somewhat twisted. The
upper ends of the thallus are more or less emarginate with obtuse
corners.
A transverse section of the thallus shows that
it
is composed
of two
different
cell-tissues
(Fig.
370
a,
b).
In the middle of the thallus a layer of very large transparent
cells are found; these are about 180
fj. thick and often more than
400
fj.
long. Seen from above these
cells have more or less undu-
lated walls and are mostly one and a half to twice as long as broad
(Fig. 370 c). For the most part this tissue consists of a single layer
of
cells, but a few times
I have found the large
cells divided into
a number
of smaller
cells (compare
Fig.
370 a).
The epidermal layer consists, in the parts nearest to the large
25
386
cells in the middle,
of irregularly shaped, tri-polygonal
cells with
elongated
corners;
from
these
cells
short,
several times
forked,
moniliform filaments emerge, these being composed of small oval
cells
(Fig.
370 a, b}. The
cells in the filaments
are about 67
//
thick.
The consistency of the thallus
is very gelatinous.
I
have
referred
this doubful plant to
Gloiocladia as
it,
to a
great
extent,
bears a
close resemblance
to
this genus.
Of
Gloio-
Fig.
370.
Gloiocladia spec.
a, transverse
section
of the
thallus (about 80:1);
b, part
of the same more
magnified (ahout
300:1);
c,
cells from the middle
of the
thallus seen from
above (about 300:1).
cladia a
single representative,
G. furcata from the Mediterranean
Sea,
is known up to the present time (compare ZANARDINI,
Ico-
nographia Phyc. Adriat.,
vol.
I,
p.
13,
pi.
4 A). When compared
with this plant the West Indian one differs nevertheless in several
respects. Thus
it must be pointed out that
its thallus
is broader
and
flat throughout
its whole length and the upper ends
of the
thallus
are obtuse.
As to the anatomical structure the most
essential
difference
between the two
plants
is that
while the
tissue
in the
interior
of the thallus in my plant consists mostly of a single layer only,
in
the
Mediterranean
plant
with
its
thicker
thallus
this
tissue
is composed
of several
layers.
Hence,
it
is most
probable, we have to do with a new spe-
387
cies which
is
a West
Indian
representative
of
this
genus, but,
having had so very little and quite sterile material at my disposal,
I
prefer to leave
it unnamed.
The
plant was dredged
in deep
sea
at a depht
of about
15
fathoms.
St. Jan:
off Annaberg.
Subfam.
2. Rhodymenieae.
Rhodymenia Grev.,
J. Ag.
1. Rhodymenia
occidentalis nov.
sp.
Frons
plana,
membranacea,
25 cm
longa
et
ultra,
crebre
dichotomo-furcata,
subflabellata,
furcationibus
angustioribus,
la-
ciniis
ca.
4 mm
latis, margine nuda, interdum
prolifera, summis
late rotundatis, basi sub-
terete-stipitata.
Frons
ex
duobus
stratis composita, cellulis
exterioribus
corticalibus
minutis,
interioribus
ad
medium versus gradatim
majoribus,
rotundatis-
polygonatis.
Organa
fructificatio-
nis ignota.
The plant is fastened
to
the
substratum
by
means
of
a
disc
from
which proliferations often
arise. The thallus
is
flat,
membranaceous.
It
is
narrow near the base, but
scarcely quite terete
; up-
wards
it
is evenly broad-
ened out until
it reaches
its normal breadth, about
4 mm. The thallus is re-
peatedly
forked;
in the
25*
Fig.
371. Rhodymenia
occidentalis nov.
spec.
Part
of
a
plant. (About
-
3).
388
basal
part
the
distance
between
the
furcations
is
shorter than
upwards. At
each
furcation the thallus
is much narrowed being
often here only
1 mm broad.
Besides
this normal ramification
proliferations
are now and
then
issued
from
the margin
of the
thallus
especially near the
narrowings.
The
thallus
is
slightly
sinuated. The apex
of the
thallus
is broadly rounded.
From
a
transverse
section
is
seen
that
the
thallus
consists
of
cells which
are
largest
in the middle (about 150
// thick) and
flflfr
Fig.
372. Rhodymenia occidentalis nov.
spec.
a, transverse section
of the
thallus (about 125:1);
b, part
of the
cortical
layer seen from above (about 350:1).
decreasing
evenly outwards
(Fig.
372, a}.
All the
cells have very
thick walls. This parenchymatic
tissue
is surrounded by a
corti-
cal layer composed of a single layer of cells; in transverse section
these
are
roundish
polygonal,
seen from above polygonal
(Fig.
372 b).
Neither
tetraspores
nor
other
organs
of
reproduction
were
found in the
material.
Considering its entire structure
it seems to me that the plant
agrees very closely with Rhodymenia,
but,
if
its organs
of repro-
duction should be
found,
it
is,
of
course, not impossible that
it
may turn out to
be,
for instance,
a
Gracilaria.
As
to
species
of Rhodymenia with which our plant may be
compared,
Rh.
flabellifolia
(Bory) Mont.
(==
Sphserococcus
tenui-
389
Julius
Kiitz.,
Tab.
phycol.,
vol.
18,
pi.
93),
Rh.
linearis
J.
Ag.,
Rh. ligulata Zanard.
etc. may be pointed
out.
The
plant was
found
at
a depth
of about 1015 fathoms
of water.
It was growing,
apparently rather abundantly,
in the
sound between
St. Thomas and
St. Jan
as a component of the
very
rich
algal vegetation found
here.
St. Jan:
Found
in
several
places
in
the sound
between
this
island
and
St. Thomas:
off Cruz Bay,
near Great
St. James,
off Hermitage,
off
Annaberg.
Coelothrix
nov.
gen.
Frons
rigida,
filiformis,
ex
numerosis
filamentis
arete
con-
junctis orta, tubulosa, in interiori parte cava, irregulariter ramosa,
ramis
sparsis, interdum
secundis
et inter se conglomeratis, inter-
dum anastomosantibus
csespites densos formantibus.
Frons
ex
duobus
stratis
composita,
exteriori
cortice
uni-
strato,
cellulis
minoribus
densis,
interiori
cellulis gradatim ma-
joribus,
rotundatis-polygoniis,
cavitatem
versus
glandes
sparsas
gerentibus.
Tetrasporangia apici
inflato
ramorum
inha-
bita.
1.
Coelothrix
irregularis
(Harv.)
Cordylecladia?
irregula-
ris
Harv.,
Nereis
Bor.-Am.,
part
II,
p.
156.
When
HARVEY
re-
ferred
this
plant
to
the
genus
Cordylecladia
he
put, no doubt correctly, a
query behind the name as
the structure of this plant
differs greatly from that
of the type species: Cordylecladia
erecta,
a
transverse
section
of
which
being
very
like
that
of Gracilaria.
Considering the struc-
ture of the thallus, especially since this is hollow as already pointed
out by HARVEY, and
the glands found upon the
cells facing the
Fig.
373.
Coelothrix
irregularis
(Harv.).
Part
of a plant. Below two branches with
anastomose. (About
4:1).
390
cavity, the
plant seems to me to be much
closer related
to,
for
instance,
Chrysymenia
and
Chylocladia, even
if
it
cannot
in
a
natural way be
referred to any
of
these
genera. On account
of
this
I
propose
to
consider
it
as
a representative of a new genus.
I
have
not
found
this
plant myself and my
description
is
therefore,
unfortunately, rather
poor,
having had
but some
old
dried
specimens,
preserved
in
the
Botanical
Museum,
Copen-
hagen, at my disposal. But the plant seems to stand drying rather
n
oroU
PXDOoc
Fig.
374.
Coelothrix
irregularis (Harv.).
a, transverse section
of the
thallus
(about 275:1);
b,
longitudinal section
(about
200:1).
well and,
after having been steeped
in water, to reassume
fairly
well
its
original appearance.
P|The
plant
(Fig.
373)
forms
low
cushions
composed
of
the
rather rigid and very irregularly branched filaments felted together;
they are fastened to the substratum by means of numerous groups
of
rhizoids,
these being able to break out everywhere from the
thallus. By means
of such rhizoids the filaments in the cushions,
too,
are mutually connected;
a group
of
surface
cells grow out
rhizoid-like from both
filaments and anastomose
in
a way very
similar
to that
in Wurdemannia (comp.
Fig.
360).
The ramification
is very irregular the branches being issued,
with
shorter
or longer
intervals on
all
sides,
sometimes with
a
tendency to be
second.
391
The growing point in the apex of the thallus consists of numer-
ous filaments packed together and with diverging
apices.
A transverse section (Fig. 374 a)
of the thallus shows at the
periphery
a
single row
of oblong
cells
placed
densely
together;
these cells are about 28 p long and 16 p broad. Next to this layer
a parenchymatic tissue follows whose
cells are roundish and gra-
dually
increase
towards
the
cavity
being
at
the
same
time
somewhat
looser
connected.
The
innermost
cells
protrude more
or less freely into the cavity and carry now and then glands (Fig.
374 a)
A
longitudinal
section
(Fig. 374 b)
shows that the peripheral
cells are nearly square
; the
cells
of the parenchymatic tissue are
rather long, about
2
3 times
as long as broad.
The
specimens examined were
sterile;
I
thought
in one
of
the specimens to have found tetrasporangia, but a more thorough
examination showed that these originated from a Hypnea whose
filaments were
densely interwoven between
those
of
Coelothrix.
But COLLINS*) mentions having found tetraspores, and HOWE**),
too,
mentions
such
ones.
According to him "the tetrasporangia
occur on pod-like enlargements of the ends of certain branchlets".
COLLINS also mentions having found cystocarps; these "are spher-
ical and external on the branches". A more detailed
description
of these organs would be highly desirable.
In "The Algse of Bermuda" COLLINS and HERVEY name the
plant
Cordylecladia
rigens,
referring
it
to the Chylocladia
rigens
J. Ag. (= Sphserococcus rigens C. Ag.).
HOWE,
1.
c.,
p. 516 points
out that
"the type of Sphserococcus rigens Ag.
is a Japanese plant
different in structure from the Bermudian and West
Indian."
The specimens
preserved
in
the
Botanical Museum,
Copen-
hagen,
are
partly "ex
ins.
St. Crucis, misit PALLE BANG", partly
from
"St.
Jan.,
Dr. RAVN." They are labelled Sphserococcus durus
Ag.
var.
Geogr.
Distrib.:
Florida, Bermuda, Jamaica.
*)
COLLINS,
FR.
S., The Algae
of Jamaica
(Proceed. Am. Acad.
of Arts
and
Sciences,
vol. 307,
1901,
p. 255).
**) HOWE
in BRITTON,
Flora
of Bermuda,
1908,
p. 516).
392
Chrysymenia
J. Ag.
In some introductory remarks
to
a former paper
of mine*)
concerning
this
genus
I
have
pointed
out
that
the
bursting
of
the
thallus,
as
described by SCHMITZ and HAUPTFLEISCH, and the
peculiar way
in
which,
according
to
these
authors,
the
gland-
cells
in the
cavities
of the Chrysymenias
are supposed
to come
into existence does not hold good in case of a more thorough ex-
amination.
In a paper of the late Prof. KUCKUCK**), whose early
death
is
sincerely to
be
regretted,
this
prominent
investigator
Fig.
375. Chrysymenia Agardhii Harv.
a, transverse
section
of the
thallus (about
80:1);
b,
gland-cell with filaments (about 350:1).
quite
agrees with me regarding the development
of the
cavities
and glands
of the Chrysymenias.
In the same paper
I
also mentioned that the shape
of the
gland-cells and their arrangement upon the innerside of the large
wall
cells seem to be
of much
specific value.
1.
Chrysymenia
Agardhii Harv.
HARVEY, W. H., Nereis Bor.-Americana, Part. IV, p. 189, tab. XXX A.
AGARDH,
J., Epicrisis, p. 322. BORGESEN,
F., Some new or little known West
Indian
Florideae,
II.
(Bot.
Tidsskr.,
vol. 30,
1910).
*) B0RGESEN
F., Some new or
little known West Indian Floridese, II (Bo-
tanisk
Tidsskrift,
vol. 30,
1910,
p. 181).
**) KUCKUCK, P.,
Beitrage zur Kenntnis der Meeresalgen, 13, Untersuchun-
gen
liber
Chrysymenia
(Wiss. Meeresuntersuchungen.
Neue
Folge, V.
Bd.,
Abt.
Helgoland, Oldenburg,
1912).
393
A few specimens
of
this
plant have been
found. They
are
fixed
to
the substratum by means
of
a
small
disc,
having
a
cuneate rapidly expanded base which
is afterwards divided
into
several lobes.
These lobes bear along their margin several smaller
ramifications,
in my
specimens they are
of an elongated oblong
shape tapering towards both
ends.
The
thallus
is
flat,
compressed,
in
places
nearly
compact,
but
here and
there
smaller
or
larger openings
are
present
be-
tween
the
innermost
large
cells
(Fig.
375
a).
These cells
are
Fig.
376. Chrysymenia Agardhii Harv.
A, wall
of frond seen from
innerside; the
cell to the left with glands
(70:1);
B, transverse section of the wall;
the
cell in the middle with a gland (70:1);
C,
part
of
a
cell
with
glands
(170:1);
D, tetrasporangia
in the
cortical
layer
(170:1).
oblong to oval
of
shape when seen from the surface (Fig. 376 A),
in transverse
section
irregularly polygonal
(Fig. 376 B). The
sur-
face
consists
of a dense layer
of small
cortical
cells covering the
underlying large
cells completely.
On their innerside,
facing the
cavities in the
interior
of the
thallus,
one" of
the
large
cells bears here and there a few (2
4
seldom
more)
scattered
gland-cells
(Fig.
375 a,
376 A).
These
are globular to obovate.
Furthermore hyphas-like filaments grow out
in
all
directions
from the innerside
of the
large wall
cells
filling up the
cavities
more
or
less
(Fig.
375 a). These
filaments have transverse
walls
and are sometimes ramified. The
cells in the filaments are nearly
cylindrical, about 20
// thick and
five to eight times as long. Such
394
filaments
are
sometimes
issued
from
the
gland-cells
too
(Fig.
375 b}.
Only
tetrasporic
plants
occurred.
The
tetrasporangia
are
developed in the
cortical layer
(Fig. 376 D}. They are cruciately
divided and
rather
small,
about
27
jut
broad. They
occurred
in
the month
of March.
This species has been found in deep water only (about 12
16 fathoms).
St. Jan:
Off Cruz Bay and near Great
St. James;
off America
Hill
where
it was collected by Dr. TH, MORTENSEN and myself.
Geogr.
Distrib.:
Florida.
Fig.
377. Chrysymenia planifrons
(Melv.)
J. Ag.
Part of a transverse section of the thallus with tetrasporangia
(about
80:1).
2.
Chrysymenia
planifrons (Melv.)
J. Ag.
J. AGARDH,
Epicr.
p. 319.
Chrysymenia Agardhii
var. planifrons
Melville, Notes on
the Alga? of
South Carolina and Florida (Journ.
of Botany,
vol.
XIII,
1875,
p.
263).
A fragment
of a Chrysymenia with
flat
thallus
is, most pro-
bably,
referable
to
this
species.
It
originates from a tetrasporic,
and rather old
plant.
A transverse
section
(Fig.
377)
of the
thallus bears a
close
resemblance
to
that
of Chrysymenia Agardhii.
In
the middle
it
is more
or
less hollow and the
cavities
are more or
less filled up
with numerous
hypha?
issued
abundantly
from
the
large
wall
395
cells. The gland-cells
are placed in the same way, having nearly
the same shape
as
in Chrysymenia
Agardhii.
Also
in
this
plant
hypha? were found growing out from the
gland-cells.
It cannot be denied that this plant, on the whole, comes very
near
to
Chrysymenia
Agardhii
and
that
MELVILLE
is
right
in
considering it as a variety only of this species. The only difference
between the two
forms
seems
to
be that the thal-
lus
in
Chrysy-
menia planijrons
is
not
divided,
being very broad.
The
plant
was
gathered
in
the
month
of
March.
It
was
dredged in rather
deep water, about
30 meters.
St. Jan:
Off
Cruz Bay.
Geogr.
Di-
strib.:
Florida.
3.
Chrysymenia
veutrieosa
(Lamour.) J. Ag.
J.
AGARDH,
Alg.
Medit.,
1842,
p.
106;
Spec.
Alg.
vol.
II,
p.
213;
Epicrisis,
p.
323.
F. BORGESEN, Some
Fig.
378. Chrysymenia ventricosa (Lamour.)
J. Ag.
A,
large
cells
facing the cavity of the
thallus, those
in
the
middle with glands
(70:1); B,
transverse
sec-
tion
of
the
wall
with
two
glands (70:1);
C,
trans-
verse
section
of an
older part of the thallus showing
hyphee-like
filaments
growing out from the innerside
of the large
cells
(125:1).
new or little known
W.
I.
Floridese,
II,
1910,
p.
183,
fig.
3.
KUCKUCK,
Untersuch.
iiber
Chrysymenia
(Beitrage zur Kenntnis der Meeresalgen,
13,
p. 218,
pi. XIII,
figs. 1621).
Dumontia ventricosa Lamour.,
Essai
Thalassiophyt.,
1813,
p.
45,
tab.
10,
fig.
6.
Halymenia
ventricosa
Ag.,
Spec.
p.
212.
Kiitzing,
Tab.
Phycol.,
vol.
16,
tab. 86.
396
Halymenia pinnulata Ag., Aufzahlung
etc.
(Flora X,
1827,
p.
645).
Chrysymenia pinnulata
J.
Ag.,
Alg.
Mediter.,
p.
106;
Spec.
Alg.,
II,
p.
212;
Epicr.,
p.
323. ZANARDINI,
Iconogr.
Adriat.,
I,
p.
151,
pi.
36 A.
The
wall
of
this
rather
large
plant
consists
of
several
cell-
layers; innermost, towards the cavity in the interior of the frond,
the
cells
are
large, becoming smaller outwards
(Fig. 378 B). The
cortical
layer
consists
of
larger
cells
innermost,
smaller
at
the
periphery;
it
is
beautifully
figured
by
KUCKUCK
(1.
c.,
p.
219,
pi. XIII,
fig.
17)
who,
on
the
other
hand,
found
the
cortical layer composed
of
short moniliform filaments
consisting
of small roundish cells. This was not so marked in the West Indian
specimens except
in the tetrasporic
plant.
Here and there, on the innerside of the large
cells facing the
cavity in the interior of the thallus, a single one of these cells or
a few consecutive
ones bear glands
(Fig.
378 A).
These glands
are as a rule placed immediately upon the membrane of the large
cells, more rarely
I have found a few of the glands placed upon
a
small
roundish
cell
while
the
remaining
glands
were
placed
immediately upon the wall
of the
large
cell.
In specimens from
the
Mediterranean
Sea
KUCKUCK
mentions
that
he
also now
and then has found such a small cell
between the gland cell and the large
cell (compare
his
fig. 19,
pi. XIII).
The
glands seem always to be soli-
tary, but several occur on each cell.
The glands are oblong-roundish when
seen from the
side
(Fig.
378 B}.
Further, in the older part of the
thallus
(comp. my
remarks
1.
c.,
p. 181) we find hyphse-like filaments
growing out
from
the
innerside
of
the
large
wall
cells
(Fig.
378
C).
These filaments are irregularly bent,
often
swollen
in
their
lowermost
part, nearly cylindrical in their up-
per
part
consisting of
cells about 16
// thick and
6
12 times
as
long. The
filaments
are now
and
then
ramified, KUCKUCK
has
found
similar
hyphse
in
the
Mediterranean
plant. A few times
small
nearly
globular glands
occurred upon
the filamemts.
n a
noOo^0ooRo^o
Fig.
379. Chrysymenia ventricosa
(Lamour.)
J. Ag.
Tetrasporangia
in the cortical
layer
(250:1).
397
Fig.
380. Chrysymenia
Enteromorpha Harv.
(about natural
size).
The
tetrasporangia
are
produced
in
the
cortical
layer and
occur scattered over the whole thallus. They are about 20 p broad
and
cruciately
divided
(Fig.
379). KUCKUCK
gives
(1. c.,
p. 223)
a transverse
section
of the wall with
tetrasporangia.
The cystocarps are likewise found
scattered
over
the
surface
of
the
thallus; they are hemispherical
pro-
minent
and
have
an
apical
porus.
Tetrasporangia
and
cystocarps
oc-
curred
in
the month
of March.
At
the
islands
this
species has
been
found
in deep
sea only (about
12
15 fathoms);
according to BER-
THOLD*) and KUCKUCK
(1. c.,
p. 218
-19)
it
occurs too in shallow water
in the Mediterranean
Sea. But
it
is
also
found
there
in
deeper
water,
and RODRIGUEZ**) found
it even at a
depth of 130 m at the Baleares.
St. Jan: In many places in the sound between this island and St. Tho-
mas and
in
the sea
to
the north
of
St.
Jan.
Geogr.
Distrib.: Mediterranean
Sea, Morocco.
4.
Chrysymenia Enteromorpha Harvey.
HARVEY,
Nereis
Bor.-Americana,
Part
II,
p.
187.
F.
BORGESEN,
W.
I.
Floridea?,
II,
p. 185.
J. AGARDH,
Epicrisis,
p. 325.
Of this
fine
plant
(Fig.
380)
I have found
a few specimens
in deep water. They .reached a length
of more than ten cms
(in
the biggest specimen collected the basal part was absent). As des-
cribed by HARVEY, the plant, to begin with, consists of a single sac-
cate oblong frond, two
three cms. long which at
its base tapers
into a short stalk ending in a small
disc, by means of which the
plant is fastened to the substratum. From this primary sac similar,
often narrower and longer, secondary sacs are issued in
all direc-
tions, and
these
are again ramified
in the same way and
so on
*)
BERTHOLD,
G., Uber die Vertheilung der Algen
in Golf von Neapel etc.,
p. 526.
**) RODRIGUEZ,
J., Algas de
las
Baleares,
p. 254.
398
(Fig.
381). At their base the sacs taper considerebly to an almost
acute
point, while
their summits
are broadly rounded. The
sacs
are nearly
cylindrical, sometimes somewhat
flattened.
The wall
is rather thin.
It consists
of a
single layer
of large
cells which, above
their transverse
walls, are covered by a layer
of cortical cells
(Fig. 381 E). These are largest just over the trans-
verse
walls
of
the
large
cells
growing
smaller
from
here,
leaving
the
middle
of
the
large
cells
uncovered.
Seen
from
above
this
arrange-
ment gives the membrane a
very
fine,
reticular
appea-
rance.
A
transverse
section
shows
the
wall-cells
to
be
roundish -rectangular
(Fig.
381 C}\ seen from above they
are
irregularly
polygonal
or
oblong,
two
three times as
long as they are broad
(Fig.
381, A\
On
the innerside
facing
the cavity
one
of
the
large
cells
bears
now
and
then
glands
(Fig. 381 A, C). These
are obovate-oval to pyriform,
when
seen
from
the
side,
and
of
rather
variable
size.
Fig.381. ChrysymeniaEnteromorpha Harv.
A,
wall-cells
facing the
cavity, the one
near the middle with
a group of glands
(70:1);
B,
a
cell
with
glands
(70:1);
C,
transverse
section
of the
wall, one
of the cells with glands (70:1); D, glands
(70:1);
E,
part
of the wall seen from
above (compare the
text)
(125:1).
They
occur
scattered
or in
small groups upon
the
surface
of the
mother-cell
(Fig. 381 B}.
A number of ten or more can be found upon the same
cell.
At the
constrictions between the
sacs there
is a tissue con-
sisting
in
the middle
of very large
cells covered by smaller ones
(Fig. 382 a). From the large
cells some small ones forming shorter
chains protrude into the cavity of the vesicles.
In the upper end
of
these
cell-chains
glands
sometimes
are
found.
Similar
short
chains
of
cells have been observed by KUCKUCK
in Chrysymenia
microphysa.
Plants with
tetraspores
did
not
occur
in my
material. But
399
Fig.
382. Chrysyinenia Enterornorpha Harv.
a,
transverse section
of the
constriction between the sacs (about 80:1);
b, a cystocarp seen from above (about
80:1).
in
the "Phycotheca Bor.-Am.",
No. 386,
a
tetrasporic specimen
from Key West
is found. The tetraspores are scattered over the
whole
surface
of the thallus
in the
cortical layer and
are cruci-
ately
divided.
Of a female plant a fragment only was gathered.The cystocarps
are scattered over the surface
of the thallus
; they are hemi-
spherical prominent and pro-
vided
with an
apical
porus.
Fig. 383 shows a longitudinal
section
through
the
middle
of
a
nearly
ripened
cysto-
carp
;
in the middle the pla-
cental
branch
is
seen
from
which
the
gonimoblasts
are
formed.
Seen from above the
cystocarps
form
spherical
r
Fig.383. Chrysymema Enteromorpha, Harv.
bodies
( Fig.
382 b).
Longitudinal section through the middle
This
plant was
dredged
of a cystocarp (about 70:1).
400
in
deep
water
(about
12
15
fathoms). Cystocarps were
found
in the month
of March.
St. Jan:
Off Cruz Bay,
off America
Hill.
Geogr.
Distrib.: Key West.
5.
Chrysymenia pyrifonnis B0rgs.
F. B0RGESEN, W.
I.
Florideae,
II,
p.
187
(Botanisk
Tidsskr.
vol.
30,
1910,
p. 187).
The plant
(Fig.
384) reaches a height
of about 4V2 cm (the
largest specimen
collected,
the
smaller ones were about two cm
only).
It
is
fastened
to
the
substratum, stones, shells etc.,
by
means
of
a
rather
large,
flat
disc;
from
this
disc, one
or
more,
erect
shoots
grow
up.
The
stem
of
these
erect
shoots
is
terete and
solid.
It
bears the
swollen,
hollow and
short
shoots
(Fig.
385).
The
shape
of
these
is
obovate-
pyriform reaching a length of
about
8 mm and
a breadth
of 5 mm.
The plant
is, when living,
somewhat
translucent.
The
colour
is
red
with
a yellow-
brown
tinge. With the excep-
tion of the stem, which
is firmer, it
is
of a rather
soft and slimy
consistency and adheres
strongly to
the paper.
As
to the anatomy
of the
thallus, we
find
the
wall
of the
vesicles consisting of a layer of large
cells
(Fig. 386 A) which on
their outer
side
are covered more
or
less completely by a layer
of small
cells
(Fig.
386 B). Seen from the
surface the innermost
large
cells show themselves
to
be roundish
polygonal
(Fig.
386
B, C}. Above the transverse walls
of the large
cells, where some
more
space
is
left on
account
of
the somewhat
curved
surface
of these cells, we find a row of roundish cells and from these again
smaller
and
smaller
roundish
cells
grow
horizontally
out
over
the surface of the large wall-cells (Fig. 386 B).
In younger vesicles
Fig. 384. Chrysymenia pyriformis B0rgs.
About natural
size.
401
Fig.
385.
Chrysymenia
pyrifonnis
Borgs.
A little magni-
fied (about
this
cortical
layer
leaves
a
space
free
over
the
middle
of
the
large
cells,
while
in
older
vesicles
the cortical cells very often cover them completely.
The
wall
of the
vesicles
is about 90 p thick. The
cavity
in the
interior
is
filled with mucilage.
A
transverse
section
of
the solid stem
(Fig.
387) shows great likeness
to
that
of Chrysymenia
microphysa Hauck
as drawn
by
KUCKUCK
(1.
c.,
p.
210).
The
cells
are
largest
in the middle, de-
creasing gradually towards the
periphery.
On the inner side of the large
cells, facing the
cavity
in
the
interior
of
the
vesicles, we
find
here and there groups of gland-cells (Fig. 386 A, C).
These are pear-shaped, occurring from two to about
eight
together
in
a
bunch.
Sometimes,
too,
a
solitary gland-cell
is present. The cells bearing the
gland-cells are mostly
smaller than the surround-
ing
cells.
Only
sterile
plants have been gathered.
Compared with Chrysymenia microphysa Hauck
- of which
we
have
a
detailed
description
since
I
described
this
species
by
the
late
Prof.
KUCKUCK
our
plant
differs
essentially
by
its
larger
size,
larger and different-
ly shaped vesicles of
which the Mediter-
ranean plant most-
ly bears but a single
terminal
one upon
each stem. Further-
more,
glands
are
not found in the Me-
diterranean
plant.
Of
the
hitherto
known
Chrysyme-
ma-species
in
the
West Indian waters
this
plant
comes,
as
I
have
already
FiS- 386 - Chrysymenia pyriformis Borgs
A, transverse
section
of the
wall,
in
the middle a
ce ii
with
glands
(70:1).
B, part of the wall seen
from
the surface
(70:1).
C, large
cells
of the wall
facing
the
cavity,
one
of
the
cells
with
glands
26
402
pointed
out,
nearest
to
Chrysymenia
Uvaria.
But among other
characters,
e.
g. the small
size of the thallus in comparison with
that
of
Chr.
Uvaria,
it
is
easily distinguished from
this
species
by
the
pear-shaped
vesicles,
in
Chr.
Uvaria
nearly
spherical,
and by the
fact
that
the
vesicles
are larger in
Chr. pyriformis.
In
the
anatomical
characters
also,
for
instance
in
the
shape
and
occurrence
of
the
glands,
a
great
difference may be
seen
when
comparing the
descriptions
and
figures
of
both
species.
This
species was dredged in
deep
water
only,
at
about
15
-16 fathoms.
Found
in
the
sea
to
the north
of St. Jan:
off. America
Hill west of
Thatch
Island.
Geogr. Distrib.
: Found
at the
Bermuda
Isles by COLLINS.
6.
Chrysymenia Uvaria (L.)
J. Ag.
J. AGARDH,
Algae maris Mediter-
ranei
et
Adriatici,
p. 106;
Epicrisis,
p.
324;
Florideernes Morphologi,
tab.
XVI,
figs. 2022.
HARVEY,
Nereis
Bor.-Americana,
Part
II,
p.
191,
pi.
XX,
B,
flgS. 13.
B0RGESEN,
F.,
W.
I.
Floridea?,
II,
p. 189.
KUCKUCK,
P., Untersuchungen liber Chrysymenia
(Beitr.
z.
Kentn.
d.
Meeresalgen,
13,
p.
214,
pi.
13,
figs.
14
15).
Fucus
Uvarius
L.,
Syst.
Nat.,
1767,
II,
p.
714.
Gastrodonium uvaria
Kiitz., Spec. Alg.,
p. 865; Tab. Phycol.,
vol. XV,
tab.
97.
As pointed out by KUCKUCK, the West Indian plants attain
a much
larger
size than those found
in the Mediterranean
Sea.
Several
of my specimens reach
a height
of up
to
20
cms. The
American specimens
are
proportionally more
slender than those
from
the
Mediterranean
Sea, and
the
distance between the ve-
sicles
is mostly
larger.
As to the anatomy, the wall of the vesicles consists inwardly
towards the cavity of
larger
cells, and of
smaller outwardly
( Fig.
388
A).
The
cortical
layer
is
dense
(Fig.
388 C);
covering
the underlying
large
cells
completely. The
large
cells
are, when
Fig.
387.
Chrysymenia pyriformis Borgs.
Transverse
section
of the stem.
(About 65:1)
403
seen
from
above,
polygonal
(Fig.
388 B],
in
transverse
section
roundish-oblong.
Towards
the
cavity
in the
interior
of the
vesicles the
large
cells (about a third part of them) bear here and there gland-cells,
which
are
rather
regularly
distributed
(Fig.
388
B}. They are
nearly
always
solitary,
a
single
one
in
the
middle
of
each
cell;
a
few
times
I
have found two, but
distinct glands, upon
the
same
cell.
The
glands
are
nearly
spherical.
According
to
KUCKUCK
the
glands
do not
occur in
the Mediterranean plants
or
are
at
any
rate
very
rare.
In
a
specimen
from
Ajaccio,
Corsica,
which
I
gathered
there
in Novem-
ber
1897,
I
found
glands
rather
abundantly;
they
were
larger than
those
of
the West
Indian
form,
of
oval
to
oblong
shape, and
occurred
singly, but mostly
quite
near
the
cross-walls
of the large
cells.
Transverse sections and
longitudinal sections
of the
massive
stem
of the West
Indian
plant seem
quite
to
agree with
KUCKUCK'S
description.
The above mentioned
differences,
regarding not only the ex-
ternal appearance of both plants but also their anatomy, show that
the American plant does not exactly agree with the Mediterranean.
I
propose to call the American plant var. occidentalis, the differences
between them not being
of
such importance that a
specific
dis-
tinction
seems necessary.
All my
material
was
sterile,
but KUCKUCK
gives
fine
ill-
ustrations of a part of a tetrasporic plant and of a transverse sec-
tion
of a cystocarp.
At the
islands the
plant was found
in deep water
only,
at
a depth of about 12
15 fathoms, while in the Mediterranean sea
it
is
also found
in shallow water.
26*
Fig.
388. Chrysymenia
Uvaria
(L.)
J. Ag.
A, transverse section of the wall, the upper-
most of the
large
cells
facing the cavity
with
a gland
(70:1); B,
large
cells, facing
the
cavity,
some
of
these
with
glands
(70:1); C, part
of
the
cortical layer seen
from above
(150:1).
404
St. Jan:
In
the sound between
this
island and
St. Thomas and
in
the sea
to
the north
of
this
island.
Geogr.
Distrib.: West
Indies, Morocco,
Mediterranean
Sea, Canary
Islands.
Coelarthrum
B0rgs.
1.
Coelarthrum
Albertisii
(Piccone)
B0rgs.
B0RGESEN,
F., some new
or
little known West
Indian
Floridese,
II
(Bot.
Tidsskr.,
vol. 30,
p. 189,
1910).
Chylocladia Albertisii Piccone,
Crociera del "Corsaro" alle
Isole Madera
e Canarie
del Capitano Enrico
d'Albertis,
p.
37,
tab.,
fig.
3
5,
1884.
C
Fig.
389. Coelarthrum
Albertisii (Piccone) Bergs.
A,
part of a plant
(about natural
size);
B, part
of a female plant
(about
2:1);
C,
transverse section showing the diaphragm between the joints (10:1).
As mentioned
in my
former
paper
this
plant was
at
first
found
at the Canary
Isles by PICCONE and described by him
as
Chylocladia
Albertisii.
Referring to my above quoted paper with
regard to my reasons
for considering this plant a representative
of a new genus,
I
shall here restrict myself to a short
description
of the
plant.
Coelarthrum
Albertisii
forms
small
bushes
about
4
5 cm
high. The
thallus
is
nearly
terete,
articulate,
hollow,
repeatedly
dichotomously
ramified
(Fig.
389 A).
The
joints
are
largest
in
the basal
part,
in my specimens oblong obovate
of shape, about
1 cm long and
l
/z cm broad; upwards the joints become gradually
smaller and
nearly spherical.
Between the joints diaphragms are
present dividing the cavity in the interior into as many compart-
ments
as there
are
joints
(Fig.
389 C, 390 A).
The membrane consists of a layer of rather large cells oblong-
rectangular when
seen
from
the
surface
(Fig.
390 D,
"), more
roundish-quadrangular
in
transverse
section
(Fig. 390 A, B, C.)
405
Towards
the
surface
these
cells
are
covered
by
a
cortical
layer,
this
consists
of
oval
roundish
cells forming a more
or
less dense
cover. Above the
cross-walls
of the cells, where these,
Fig. 390.
Coelarthruin
Albertisii (Piccone)
Borgs.
A,
transverse
section
of
a' joint
at the apex of the thallus (about 10:1);
B,
C,
transverse
sections
of
the
wall, B with a gland, C with tetraspores
(70:1);
D,
large
cells
of
the wall seen from
the inner side
(70:1); E, do.
with
glands
(150:1);
F,
the
wall
seen from
the surface showing also the
underlying
cells (150:1); G, part of the cortical layer with tetraspores (150
: 1).
because
of
their
roundish
shape,
leave some
space open, some
larger
cells
are
found
(Fig.
390 F)
and
from
these
larger
cells
smaller
ones
are
given
off
growing
out over the surface of the
large
wall-cells.
The diaphragms consist
of a single or two layers
of
cells
ac-
406
cording to the dimensions
of the
cells.
Here and there, towards
the cavity in the interior of the
thallus, some
of the
cells in the
membrane
and
diaphragms
bear some
smaller,
irregularly
stel-
late
cells
provided
with
shorter
or
longer
prolongations
(Figs.
390 .A, #,(7). Some
of
the
prolongations
of
these
cells
are
con-
nected with the adjacent
cell
as seen
in
Fig.
391.
Upon the
stellate
cells one
or, more
rarely two
nearly
glo-
bular
or short pyriform glands occur
(Figs.
390 E,
391).
I
have
found
only
tetrasporic
plants.
The
tetrasporangia
Fig. 391.
Coelarthrum
Albertisii (Piccone)
Borgs.
Membrane-cells from the inner
side with stellate cells and glands.
(About 275:1).
are formed
in the
cortical layer and
are cruciately divided
( Fig.
390 G). Their diameter reaches a length
of about 25
IJL. The tetra-
sporic plants were gathered
in the month
of March.
The cystocarps occur, according to a specimen from Guade-
loupe
collected by SCHRAMM,
scattered
over
the
thallus
(Fig.
3895);
they
are
hemispherically prominent and
provided
with
a small
apical
porus.
At the islands this plant has been dredged only once in the
sea to the north
of
St. Jan:
off America
Hill west
of Tortola.
I
discovered
it in a collection of several living alga? which Dr. TH.
MORTENSEN,
visiting
the
islands
for
zoological
investigation,
most kindly sent
to me.
It was dredged in deep water (about 15
fathoms)
in rather open
sea.
Geogr.
Distrib.: Canary
Islands, Guadeloupe, Bermuda.
407
Champia
Desv.
1.
Champia parvula (Ag.)
Harv.
HARVEY, W.
H., Nereis Bor.-Am.,
part
II,
p.
76.
J. AGARDH,
Epicri-
sis, p. 303. FARLOW, W. G., The marine Algae of New England, p. 156, pi. XV,
figs.
2
5.
DE-TONI,
G.
B.,
II
genere Champia
Desv.
(Memorie
d.
Pont.
Accad.
del Nuovi
Lincei,
vol. XVII, Roma
1900,
p.
11).
Chondria parvula Ag., Systema,
p. 207.
Gastridium parvulum
Grev.,
Alg.
Brit.,
p. 119.
Chylocladia parvula Hook.,
Brit.
Flora,
II,
p.
298. HARVEY, Phycolog.
Brit.,
tab. 210.
Lomentaria parvula KUTZ.,
Spec.
alg.
p.
864;
Tab.
Phycol.,
vol. XV,
tab. 87;
J. AGARDH,
Spec.
Alg.
II,
p. 729.
Fucus
kaliformis,
y nanus Turner,
Fuci,
p. 61.
For more synonyms compare DE-TONI, Sylloge
Alg.,
vol. IV, part
II,
p. 558.
Many
investigators
have
been
engaged upon the examina-
tion
of
this plant;
I
mention below the
chief
authors and
their
papers.
BERTHOLD 1
) in his useful treatise has given some short notes
on
this
alga,
but DEBRAY 2
)
and BIGELOWS
) were
the
first
to
give
a more
detailed
description
of
the
structure
of
it.
Their
papers
were worked
out
quite
independently
of
each
other
at
about
the same time. A few years
later,
in
1890, DEBRAY pub-
lished
a "2me
Memoire",
Sur
la
structure
et
le developpement
des
Chylocladia, Champia
et
Lomentaria4
)
in
which
he
ampli-
fies
his
former
paper.
Later
on
DAvis5
)
has
given
a
detailed
description
of
the
development
of
the
frond
of
Champia
from
the
carpospore,
and
in
the
same
year
HAUPTFLEiscH 6
)
gives,
besides
a
short
description
of the
vegetative
structure
of
1
) BERTHOLD,
G., Beitrage
zur Morphologic und
Physiologie der Meeres-
algen.
(Jahrb.
fur wissensch.
Botanik, Bd.
13,
1882,
p.
686).
2
) DEBRAY,
F., Recherch.
sur
la structure
et
le developpement du
thalle
des Chylocladia, Champia
et Lomentaria
(Bullet,
scient. departem. du
Nord,
2
serie, No. 718,
Paris).
3
) BIGELOW,
R.
P., On
the
structure
of the
frond
in Champia parvula
Harv.
(Proceed. Amer. Acad.
of Arts & Sciences,
1887,
p.
111).
4
)
In
Bulletin Scientifique de
la France et de
la Belgique, tome 22, 1890).
5
) DAVIS,
B.
M., Development
of
the
frond
of Champia parvula,
Harv.
from the carpospore (Annals
of Botany,
vol.
6,
1892,
p.
339).
6
) HAUPTFLEISCH, P., Die Fruchtentwickelung der Gattungen Chylocladia,
Champia und Lomentaria
(Flora,
vol.
75,
1892,
p. 307).
408
the
plant,
a
description
of
the
development
of
the
cystocarp.
And
finally,
in
1896,
DAvis 1
)
published
a paper
in which
he
gives
a
very
detailed
description
of
the
development
of
the
cystocarp
in
Champia par-
vula.
Referring to these exa-
minations
with
regard
to
the
structure and
develop-
ment
of
the
plant,
I
shall
only
mention
here
that
I
have
often found the plant
creeping
on
the
leaves
of
Thalassia
as
well
as
on
larger
algaB,
for
instance,
Udotea
Flabellum
or
Hali-
meda.
The
filaments
are
more or less decumbent and,
from the nodes on that side
of the
filaments
facing the
hostplants,
groups
of
sur-
face
cells grow out forming
short
hapters
by
means
of which the plant attaches
itself
to
the
substratum
(Fig.
392).
The
tetraspores
are
formed
in
the
peripheral
layer
in
broad
belts
com-
prising
several joints, gene-
rally
rather
close
to
the
apex
of branches
(Fig. 392).
The antheridial stands ( Fig. 393) form small roundish patches
which
often cover
several
coherent
joints rather densely;
some-
times the whole upper
part
of
a branch
is
covered.
DAVIS has
1. c.,
1896,
pi. VII,
fig.
1 figured a part of a male plant in which
these
often large zones
of
antheridial
stands
are
seen.
A few young female plant have
also been found; the cysto-
Fig.
392. Champia parvula (Ag.) Harv.
a, part of a
creeping
filament with
rhiz-
oids
and
tetrasporangia
(about
22:1);
b,
one
of
the
bundle
of
rhizoids more
magnified (about 60:1)
DAVIS, B. M., Development of the cystocarp of Champia parvula (Bot.
Gazette,
vol. 21,
1896,
p. 109).
409
carps occur
scattered,
solitary or
a few together upon the same
joint. DAVIS has
1.
c.
described
their development.
This plant was found with tetraspores
in the months Janu-
ary
to March
and
with
antheridia and
cystocarps once in Feb-
ruary.
It occurred
in shallow water both
in
sheltered and
in more
exposed
localities and
in deep water down
to
a depth
of about
20 fathoms. In deep water and
in
sheltered
localities,
for in-
stance
in lagoons, the plant is
slender
and
the
joints rather
long, in more exposed places
it
is
more
robust
with
short
joints.
St.
Croix:
Christianssted's
Lagoon,
Christianssted's
Harbour,
oft Frederikssted, Krause's Lagoon.
St.
Jan:
Off
America
Hill,
off
Ramshead.
Geogr.
Distrib.:
Warmer
parts
of the
North-atlantic Euro-
pean
and
American
coasts,
Me-
diterranean
Sea.
G , n v-O'^Cv^
%%
<?>eo
'. 393. Champia parvula
(Ag.) Harv.
.4,
part
of
the wall seen from above
and B, transverse
section
of
the wall
of a male plant
(350:1).
2. Champia salicornoides Harvey.
HARVEY,
W.
H.,
Nereis
Bor.-Am.,
p.
76,
tab.
XIX
B.
AGARDH,
J.,
Epicrisis,
p.
305.
This
species
bears
a
rather
close
resemblance
to
Champia
parvula
not
only with regard
to
its outer habit, but
also
in
its
anatomy. BIGELOW has pointed this out in his paper quoted above
on
p.
118. But Champia salicornoides
is a much bigger plant and
when
examined
more
thoroughly,
some
anatomical
differences
also become
apparent.
The
peripheral wall
of the
frond consists of a single layer of
cells,
seen from above rectangular
polygonal, about l
j
/a to 2 times
as long as broad
; in transverse section the
cells are nearly square-
shaped.
The
cells
have
a
rather
thick
peripheral
wall
which
swells
greatly
in
water. The diaphragms between
the
joints
of
the thallus consists of a single layer of cells of irregular, polygonal
410
shape when
seen from above
(Fig.
394^4), more
rectangular
in
transverse section
(Fig. 394 B).
On the inner side
of the
wall we
find the
vertical filaments
(Fig.
394 5, D).
These
are
often
in
quite
close
connection with
the wall-cells, sometimes even somewhat immersed in their thick
membrane
(Fig. 394 C}. The filaments run from the apex
of the
branches to the bottom and
pass through the diaphragms
(Fig.
394 A, B).
The
cells
of the
filaments
are about
16 ^ thick and
Fig. 394. Champia salicornoides Harv.
A,
transverse
section
of
the
wall
(to
the
left),
to the right part
of the
diaphragm seen from above
(50:1); B, transverse section
of the diaphragm,
to the
left with
a part
of the wall
(30: 1);
C, transverse section
of the wall
and a filament
with
a gland
(50:1);
Z>, the wall seen from the inner side
with
filaments
(30:1);
E,
wall-cells with glands seen from above
(150:1);
F,
part
of
the
same
in
transverse
section
(150: 1);
G, apex
of a branch
seen
from
above
(150:1);
H,
part
of
the
wall
with
tetraspores
(50:1);
/,
tetraspore
in transverse section
(50:1).
about ten times as long.
They bear one, or sometimes, two oppo-
site
gland-cells
placed
about
the
middle
of the
cell. The glands
are
nearly
spherical
or somewhat ovate
(Fig. 394 C).
As a rule
the filaments
are not
ramified, but once a side-branch was found
connecting the filament with one
of the adjacent filaments.
Among the larger wall-cells some smaller ones, rather regularly
distributed,
are generally present
(Fig. 394 E)
; like the large
cells
the
small
ones,
too,
are connected by means
of pores with the
411
adjacent
cells. These small
cells
are mostly rather
flat and from
their upper (outer) side a small oblong
cell merges vertically into
the
thick
peripheral
wall
(Fig.
394 F).
These
cells
are
formed
very
early
together with
the
other
large
cells and
are
already
observable
in the quite young parts of the thallus, and they are
easily
recognizable
by
means
of
their
homogenous
and
more
refractive
contents. When
treated
with
Chlor-Zinc- Iodine they
are
coloured
yellow
like
the
large
wall
cells
and
treated
with
Ha3matoxylin
they
assume
also nearly the same tinge
of colour
as
these.
Most
probably,
as
I have already pointed out
in my
above
quoted
paper, we
have
to do with
a kind
of
gland-cells
from
which
is
secreted
the mucilage
in which the
living
plant,
as
far
as
I remember,
is mostly imbedded.
The
apical
growth
of the
plant
seems
to
agree
fairly
well
with that
of Champia parvula
as described by BIGELOW.
As
I have pointed out already in my paper mentioned above
I cannot agree with BIGELOW when he
says that "the branches
in Champia salicornoides do not come
off
at the nodes, but may
spring from any
part
of the
internodes";
in my specimens
the
branches always
issue
at the diaphragms.
The tetrasporangia
are formed
in the
wall
in the
following
manner. A small cell is cut off now and then from one of the larger
cells.
This becomes to a great extent filled with contents and gra-
dually
increasing
in
size becomes
the mother
cell
of the
tetra-
sporangium.
The
tetrasporangia occur scattered over the whole
surface
of
the
branches;
a
transverse
section shows that more
than
half their length emerges into the cavity
of the
joints.
The cystocarps
are rather prominent, urn-shaped and occur
scattered over the
surface
of the
thallus.
Among the
dried specimens
a
single male plant was found.
The antheridial stands are very like those in Champia parvula and
occur over the whole surface
of the
plant.
FARLOW and later on DE-TONI in his paper: "II genere Cham-
pia Desv." have considered this species only as a variety of Cham-
pia parvula. As mentioned above Champia salicornoides certainly
is closely related
to Champia parvula. But Champia salicornoides
is a much larger plant, and the arrangement of the tetrasporangia
is
not
the same and some
anatomical
differences
are
also
pre-
sent, for instance there are several more vertical filaments in this
412
species
than
in Champia
parvula,
and
the
filaments have more
cells in each
joint than
in Ch. parvula.
Plants
with
tetraspores
and
cystocarps
were
found
in
the
month
of March; antheridia in January.
It was gathered mostly
in deep water (about 1415 fathoms), once in shallow water near
the shore
in a rather protected
place.
Found at St. Jan.
in several places
in the sound between
this island
and
St. Thomas, near Mary
Bluff (by
Dr.
TH. MORTENSEN),
off America
Hill,
Coral Bay.
Geogr.
Distrib.:
Florida.
List of the Chlorophycece,
Phceophycece and
Rhodophycece found
at the islands together
with addenda and
corrections.
Chlorophyceae.
1.
Enteromorpha
flexuosa (Wulf.)
J.
Ag.
2.
chaetouiorphoides
Bergs.
3.
lingtilata
J. Ag.
4.
plumosa
Kiitz.
5.
clathrata (Roth)
Greville.
6.
Ulva Lactuca L.
7.
fasciata
Delile.
8.
Blastophysa rhizopus
Rke.
Besides
the
plant
I
previously
found
growing
in Nemalion
Schrammi
I have now found
it, once more, rather abundantly in
Dictyota
indica, where
it occurred
in
the epidermal
cell-layer to-
gether with Phseophila Floridearum and Endoderma.
Seen from above the
cells are oval to oblong, but
still many
of them are of a very irregular shape (Fig. 395 a). The cells contain
a great number af roundish or polygonal chromatophores, a pyre-
noid being present in the middle of some
of those.
The
cells are
about 100 p long and 50 a broad.
Sometimes
the
cells
lie
quite
closely
together,
sometimes
with some distance between, being then connected with a shorter
or longer tube (comp.
Fig. 395
a,
fc); this
is about 8
10
/* thick.
414
The
hairs occur upon the external
side
of the
cells in groups
of
about two to six; the hairs are about 3
ju thick.
Fig. 395
c, d
shows tranverse
sections
of the epidermal
cell-
layer of Dictyota in between which the Blastophysa is seen immersed;
Fig.
395. Blastophysa rhizopus Rke.
a, seen from above,
b, plant from near the margin of Dictyota.
c and
d, transverse sections.
(About 200: 1).
in the one figure two cells are seen lying below the epidermal cells
of the
Dictyota,
in the
other
figure
a
single
thicker
cell
is
seen
between the
cells of the Dictyota.
The Dictyota was dredged in a depht of about 10 meters.
St. Croix:
off Frederikssted.
415
9.
Phaeophila Floridearum
Hauck.
HAUCK,
F.,
Verzeichnis
der
im
Golfe
von
Triest gesammelten
Meeresalgen (Oesterr. bot. Zeitschr.,
1876, pp. 56,7). HUBER,
I.,
Contri-
butions
a
la
connaissance
des
Chaetophorees
epiphytes
et
endo-
phytes
(Ann.
sc. nat.,
7.
ser.,
bot.,
t.
16,
p.
326,
pi.
XVI).
This plant has been found
several times as an endophyte
in
different
Floridex,
for
in-
stance
in
Liagora
pinnata,
Laurencia
Poitei,
Griffithsia
Fig. 397. Endoderma viride (Reinke) Lagerheim.
a, plant
from
Chrysyrnenia
Agardhii.
b, from
Champia salicornoides. c, from ChrysymeniaEnte-
romorpha.
d, from Champia parvula.
(a, b, about
200:1;
c,
d, about
150:1.)
Fig. 396. Phseophila Floridearum Hauck.
a, seen from above,
b, transverse^ sec-
tion. (About
200:1).
glob ifera and Champia
parvula.
Furthermore
1
have found this plant
growing in the epider-
mal
layer
of Dictyota
indica (Fig. 396). The
cells reached a length
of
about
50 ^ and a
breadth of about 25 \a.
The
hairs
are
about
4
(LI thick. The
figure
shows partly a piece of
the plant together with
the
epidermal
cell-
layer of the host, partly
a transverse section of
the Phseophila immer-
sed
in
the
epidermal
layer of the
Dictyota.
St. Croix:
of! Fre-
derikssted,
Long
Point,
near Buck
Island.
Geogr.
Distrib.:
Mediterranean
Sea,
At-
lantic coast
of Europe.
416
10. Endoderma
viride (Reinke) Lagerh.
Once more
I have found this plant upon Chrysymenia Agardhii.
Several
of
the
specimens
had
zoospores,
a
smaller
or
larger
part
of
the
cells in the middle
of the plant being emptied. The
Fig. 397
a shows such a plant.
It was gathered in the month
of
January, and
the
host
plant was
dredged
in
deep water about
30 meter,
at
St. Jan:
off America
Hill.
In
several
other
plants
I
have
found
forms
of Endoderma
which
I think are referable to this species, even
if they mutually
show differences both as to the shape of the
cells and as to their
way
of growing in the various host
plants.
In a specimen
of
Champia
salicornoides an Endoderma was
found
of which the
Fig.
397
b shows
a
small
piece.
As
is
seen
from the figure it forms a network composed of the jointed branch-
ing
filaments
which
follow
the
outlines
of
the
large
wall
cells
of the host plant
in a way very
similar to that found
in forma
Nitophylli COTTON 1
).
If we compare COTTON'S
figure
1 with my
figure the likeness seems very striking. The diameter of the
cells
is about 3
6, the thickest cells reaching a breadth of up to 10
//.
The cells were crammed with starch, and the shape of the chrom-
atophore was
not
recognizable.
This
plant was dredged
in deep
water
about
15
fathoms
in
the Sound between
St. Jan and
St. Thomas: near Great
St.
James.
A very similar form was found in Champia parvula.
Fig. 397 d
shows a small piece of this Endoderma. The cells are a little shorter
here, but
the
breadth of the
cells are nearly the same as in the
case
of the form found in Champia salicornoides.
It was dredged
off Frederikssted,
St. Croix,
in
a depth
of about
10 meters.
In
the
epidermis
of
Chrysymenia
Enteromorpha
an
other
form
(Fig.
397
c) was found which
I
think
also can be referred
to End.
viride.
It
grows
in a way
similar to that
of the above
mentioned
form
following
the
outlines
of
the
large membrane
cells.
It
is a somewhat larger plant,
its cells being from 6 to 14 p
broad. The shape of the cells
is more irregular than in the former
plant.
In many
of the
cells the formation
of zoospores was
pre-
sent and several cells were emptied of their contents.
It was dredg-
ed
off Cruz Bay,
St.
Jan,
in a depth
of about
12 fathoms.
COTTON, A. D., On some endophytic Algae (Journ.
of the Linnean Soc.,
Bot.,
vol.
37,
1906,
p.
288,
pi.
12).
417
Fig.
398.
Endoderma
viri.de
(Rke.
)
Lagerh. from the epidermis of Dictyota
indica. (About
175:1.)
Further, in the thick membrane
of Hypnea cornuta an Endo-
derma
occurred
whose
cells
were
subcylindrical
or
sometimes
more irregular with small
ele-
vations. As large cells
are not
present
in
the
cortical
layer
of the Hypnea the endophyte
creeps everywhere
at random,
forming an irregular network
by means of its filaments which
are ramified on both sides. The
cells were about
5
7 ^ thick
and up to 40
y. long. The Hyp-
nea was found in the harbour
of Charlotte Amalia, St. Tho-
mas.
Furthermore an Endoder-
ma
(Fig.
398)
was
found
in
the epidermis
of
Dictyota
in-
dica.
It
is
freely
dendritically
ramified
with
branches
issuing
from
both
sides
of
the
filaments
and
spreading widely
in
the
host, following mostly the way above the vertical walls of its peri-
pheral cells. The cells of this Endoderma have more or less sinuate
walls and reach
a
length
of up
to 30
\a and
a breadth
of up to
15
ja. The
cells are
filled with granular contents, rich in starch. In
the cells one or two pyrenoids are present. This form was dredged
off
Frederikssted,
St.
Croix
in
a
depth
of
about
10 fathoms.
A very
simi-
lar Endoderma was
found in Spyridia
filamentosa
gathe-
red
at
the
shore
of
Green
Cay
Estate, St. Croix.
In an old Cau-
lerpa another En-
doderma was found
of which
the
ac-
companying
Fig.
399
shows
some
Fig.
399. Endoderma viride (Rke) Lagerh.
Forma. Comp.
text. (About 260:1.)
418
filaments. As it is seen from the figure the irregularly branched fila-
ments are composed of cells of rather varying shape. Near the apex of
the filaments the cells are subcylindrical,but they soon obtain a very
irregular shape often with several outgrowths and narrowings in be-
tween. In older parts of the plant the filaments are packed so closely
together that they form an almost pseudoparenchymatous
tissue
(comp.
Fig. 399
d).
The
cells
are
8
11
14 a sometimes up to
20
/Jt
broad, and two
to
four times
as
long. They have
a
large
parietal chromatophore with a few pyrenoids (1
3).
All the
cells
may be transformed into zoosporangia. The
zoospores escape by
means
of a
hole
in
the
cell-wall.
I
refer
this Endoderma,
as a
forma ma/or, to E. viride.
The
Caulerpa was
gathered
in
Christianssted's Lagoon,
St.
Croix.
11. Endoderma vagans nov. spec.
Thallus
endophyticus,
in
membranis
hospitis
(Griffithsise
globiferss)
valde
circumvagabundus,
e
filamentis
repentibus,
articulatis, irregulariter ramosis compositus;
cellula? subcylindricse,
5
13 n
latae, diametro 2
4 plo vel ultro
longiores, in media parte
saepe tumorem
unilateralem vel rarius cellulam parvam gerentes;
chromatophora
parietalia,
pyrenoideis pluribns
instructa.
Zoosporse numerosse
in
cellulis
vegetativis
ortee.
In
the
thick
peripheral membrane
of
Griffithsia
globiiera
a
highly
ramified
Endoderma w
ras
found
which
I
consider
the
representative
of
a new
species
(Fig.
400).
In the
specimen
of
Griffithsia,
in which
it was discovered, it was found in abundance
and
formed
a
reticular
plate
all round the
cell
of
the
host.
In
dried
material
the Endoderma had a clear green colour.
Its
cells
are
of
very
varying
dimensions from
5 to
13 ^ thick
or more,
and
from 18 to more than 50
//
long. The shape
of the
cells
is
much varying, too;
in most cases the
cells are nearly cylindrical,
or they may have
an
elevation
on
the
one
side, more seldom
two
opposite,
one on each side. From this elevation a new branch
frequently
originates, but
it may happen, that
it is cut
off by a
wall, thus remaining
as
a small
cell
(Fig.
400 a).
The
cells
contain
a
large
disc-formed
chromatophore, cove-
ring
nearly the whole lumen
of the
cell;
in the chromatophore
several
pyrenoids
(about
5
7)
are
present
(Fig.
400
c, d). The
419
cells contain
a great deal
of starch and are coloured quite black
by
Iodine. A
single nucleus
is present
in each
cell.
In some of the
cells zoospores were present
(Fig. 400 e). The
whole
cell
with
its
elevation
is transformed
into
a sporangium.
The zoospores are about
2
(
broad and 4 /* long with acute ante-
rior end and broadly rounded
dorsal end.
They
are
formed
in a
number
of
about
15
in
each
cell,
somewhat
varying
according
to
its
size. The
zoospores
escape by means
of
a
short
channel
Fig.
400. Endoderma vagans nov.
spec. Compare text.
(a, about
150:1,
b and
e, about
250:1,
c and
d, about
500:1.)
through the membrane of the host plant which
is formed by the
elevation
of the
cell. The
cilia were not
visible.
There
is
still
to be added
that now and then the
contents
of
the
small
cells
mentioned
above
were
divided
into
several
small narrow bodies lying above each other up
to
a number
of
5
6
or more
(Fig.
400
c and
d}. They were
filled with
starch,
becoming very dark when
coloured by
Iodine. What
their
func-
tion
was
1
cannot
tell,
having
not
been
able
to
follow
their
development,
for which purpose
living material
is
necessary.
The
Griffithsia,
in which
this
plant
occurred, was
dredged
in
a depth
of about
five fathoms
in the month
of January.
St. Croix: Near Buck
Island.
27*
420
12. Endoderma ventriculosum nov. spec.
Endoderma
endophyticum
in
membranis
hospitis
(Chrysij-
menisB Agardhii)
maculas
largas
formans;
thallus
e
filamentis
articulatis,
longis,
irregulariter
subdistiche
ramosis,
undulatis
compositus;
rami
angulo
fere
recto
e
filo materno
oriuntur.
Cellulse
longa?,
subcylindricse, crassitudine
variabili,
in parte
media
inflates,
4
20 p
latse, spe 70 p long*, chromatophorum
parietalem, pyrenoideis instructum continentes. Sporangia non visa.
In the thick peripheral
membrane
of
Chrysymenia
Agardhii
an
endophytic,
widely spreading plant (Fig.
401
) of a very characteristic
appearance was found, form-
ing
patches
of
great
ex-
tensions
in
the host plant.
This plant
I think referable
to
the genus Endoderma as
a new
species.
In
dried
material
the
Endoderma was easily recog-
nizable owing to
its green
coloured
chromatophores,
filling
out
the
whole
cell
homogenuously. And, as to
material
preserved
in
alco-
hol, the plant
in this
case,
too, when
put
into
water
and
Iodine, was easily recognizable, the whole contents of the cells
being coloured
nearly black on account
of
the
starch contained
in the
cells.
The plant consists of long cells of very irregular shape form-
ing together highly ramified
filaments. The
apical
cells
are
sub-
cylindrical with obtuse summits and more or less undulated walls,
but
soon
the
cells
swell
in
the
middle,
this
swelling
occu-
pying nearly a third part
of their whole length. Because of these
swellings and, on the whole because of the very varying diameter
of the
cells, these being now thinner, now thicker and the undu-
Fig.
401.
Endoderma
ventriculosum
nov.
spec,
a, plant seen from above,
b, trans-
verse section through the host-plant with
the endophyte.
(a. about 150:1,
b,
200:1.)
421
lating shape
of the
cells,
the filaments
get
a
serpentine-like
ap-
pearance.
The cylindrical part of the cells is about 4 // thick, the swelled
part
often more
than
20 p.
The
cells
reach
a length
of more
than
70
//.
The
branches
are
mostly
given
off from
the
swelled
parts
of the
cells, and
it may happen that
3
to
4 branches issue from
one and the same
cell, this then becoming swelled and often very
irregularly
shaped
through
nearly
its
whole
length.
The
rami-
fication
is rather irregular, but nevertheless a certain method is pre-
sent, because
a main filament
is,
as
a
rule, distinguishable, and
from
this branches
are
given
off
at about right angles on both
sides.
In
this way the plant forms a
reticular tissue with
larger
and
smaller meshes
all over the
surface
of the
host.
The
shape
of
the chromatophore was
not
to
be
seen with
certainty in the material, but seems to be a parietal plate. There
are
several large pyrenoids
in each
cell; the
cells contain much
starch.
The Chrysymenia, in which it occurred, was dredged in about
15 fathoms
of water.
St. Jan:
off America
Hill.
13.
Ulvella
Leiis Crouan.
14.
Pringsheimia scutata Reinke.
15.
(?)
Udotese Bergs.
16.
Gornontia polyrhiza (Lagerh.) Bornet
et
Flah.
17.
Chsetoniorpha
clavata
(Ag.)
Kiitz.
18.
antennina (Bory)
Ktitz.
19.
crassa
(Ag.)
Ktitz.
20.
serea
(Dillw.)
Kutz.
21.
brachygona Harv.
Besides the above mentioned
(vol.
I,
p.
18) detached form
of this species
I have found
several fixed forms
all characterized
by
proportionally
short
cells,
but
of
rather
varying
diameter
in the filaments; but, nevertheless, as
it seems, closely connected.
How
far
these
forms
are
rightly referred
to
Cfwstomorpha
bra-
chygona
I
dare
not
say. A study upon
living material
of these
forms, which in several respects bear a close resemblance to
Uro-
spora, would be highly interesting and
instructive.
422
Fig.
402.
Chaetomorpha
bracky-
gona Harv.
a, base
of a plant.
b
and
c,
parts
of
the filament.
(About
150:1.)
others 95 p, and thinner and
thicker
parts were found
in
between each
other.
Another
form
is shown
in
Fig
403
a,
&,
c.
This
has
also
a
vigorous
basal
disc
formed by the through grow-
ing
of
the
lowermost
cells.
The
cells
in
the
vegetative
part of the filament are nearly
as
long
as
broad,
shortly
The figure 402 shows one of these
forms.
It
is fixed
to
the rocks by
means of a vigorous basal
disc; the
basal
cell
is
long
with
thick
and
lamellated wall;
it increases in
size
and is formed by the lowermost cells
of
the
filament
gradually growing
downwards into the cell below, a well
known
fact
described
by
ROSEN-
viNGE 1
).
The
cells
in
the
filament
varies in length from about half their
diameter to about as long as broad
;
they are rarely longer, but
it happ-
ens that
cells occur about twice
as
long as broad.
In this specimen the
upper end of the basal
cell
is
67
/j.
broad;
the
vegetative
cell
in
the
filament
are about 85 p. broad and
the
emptied
zoosporangia
up
to
150
p. broad.
But
I may point out
that the breadth of the filaments
is
very varying, even in the same
fil-
ament;
for
instance was a filament
in some
parts
45
IJL
thick
only,
in
In
>>Botanisk
Tidsskrift,
vol.
18,
p.
65, 189293.
Fig. 403.
Chaetomorpha brachygona Harv.
Two forms. Comp.
text. (About 150:1.)
423
Fig.
404. Chsetomorpha brachy-
gona Harv.
Two forms. Com-
text. (About
200:1).
after
division only half
their length.
The
zoosporangia,
have
nearly
the
same
shape,
though
often
a
little
swelled
in the middle.
In
this form
the
upper
end
of
the
basal
cell
is
about 40 p. broad ; the vegetative part
of
the
filaments
is 65 n broad, and
the sporangia
70
/* broad.
Parts
of
a very similar form
is
figured in Fig. 403 d, e. The vegetative
cells in
this plant reached a breadth
of about 50 p.
Finally in Fig. 404 a,
b and
c, d
two more narrow forms
are
figured.
Their vegetative
cells vary
in
thick-
ness from 35
45 //. With the excep-
tion
of those quite
close to the base the
cells
in these forms are
very short, often reaching not half their breadth.
The
specimens
here
described
and
figured
are
only
to
be
considered
as
samples.
Between them
specimens may be found
connecting them all gradually
as
to shape
and
size
of the
cells.
These
forms
were
all
growing
together
in
an
ex-
posed
locality and
found
in
company with
Enteromorpha
plumosa,
Pylaiella
fulrcscens
and
the
below
mentioned
Bhizodoniums.
St.
Jan:
Christiansfort
on
steep
rocks
facing
the
open sea
at
about
high
water mark
or a
little above.
22. Chsetomorpha gracilis
Kiitz.
Besides the detached form
Fig.
405.
Chsetomorpha
gracilis
Kutz.
mentioned
in
vol.
I,
D.
19
I
a,
b,
c t
parts
of a filament,
d, base
of
another plant.
(About
150:1.)
have moreover found a fixed
424
form which
I
think
referable
to
this
species
(Fig.
405).
It was
growing
together with the above mentioned Chaetomorpha
forms.
It
is fixed to the rocks
etc. by means
of a larger or shorter
basal
cell
formed
by
throughgrowing
of
the
lowermost
cells.
The
cells
in the vegetative part
of the filaments are about 70
80
|u thick and two to four times as long. The zoosporangia are often
a little swelled in their middle, about 85
\\. thick and two to three
times
as
long.
St. Jan:
Christiansfort.
Rhizoclonium
Ktitz.
Upon steep rocks in an exposed place near high water mark
or
a
little above some Rhizoclonium
forms were found showing
several
peculiarities.
They
occured
as
parts
of
an
interesting
association
of
alga?,
answering
to
the
North-Atlantic
Bangia-
Urospora
Association
of
the
Faroes 1
)
or
the
Bangia-Urospora-
Ulothrix
Association
of
Clare
Island 2
).
The members
of
the
tropical association were: a small
Enteromorpha plumosa, Pylaiella
fulvescens and several species of
Chaetomorpha and Rhizoclonium.
It is a well known fact that
the genus Rhizoclonium is especi-
ally
characterized
by
the
pre-
sence of
lateral
rhizoids
occur-
ring
more
or
less
abundantly,
though
sometimes
nearly
or
quite wanting, and by the
ab-
sence
of
the
original
basal
end-rhizoid,
this
having
been
found
a few times
only.
In the present forms (compare figs. 406 and 407)
all the many
specimens examined had no
lateral
rhizoids
at
all and
in most
Fig.
406.
Rhizoclonium
Kochianum
Kiitz.
Different forms with bases of
two
plants.
(About
260:1.)
x
) BORGESEN,
F.,
The
Algae-vegetation
of
the
Faeroese
coasts
(Botany
of the
Faeroes, Part
III,
1905,
p.
719).
2
) COTTON, A. D., Marine Algae,
Clare
Island Survey 15,
p. 30. (Proceed-
ings Royal
Irish Acad.,
vol.
31,
1912).
425
;
*
:
Fig.
407.
Rhizoclonium
Kerneri
Stockm.
Two
forms
with
the
original
bases, (a
e, about 260:1;
f. about 500:1.)
of
the
specimens
the
original
basal
rhizoids
were
present,
the
plants being fixed by means of them to the rocks. Most probably
the
end-rhizoid had been cut of! during the gathering in the spe-
cimens
in which
it was
absent.
The basal
rhizoid
(comp. Fig. 406 and
407)
is below broad-
ened
out
to
a small
disc with irregular coralliform
outline, and
the base on the whole becomes gradually
strengthened by means of throughgrowing
of
the
lowermost
cells
in
the
filament
down into the basal
cell in a way similar
to
that
known
so well
in
Chsetomorpha.
This
throughgrowing
can take
place
in
three to four of the basal cells, the lowermost
cell in this way becoming rather long.
As
already
mentioned
the
original
basal rhizoid in Rhizoclonium is very rarely
found.
Regarding
Rhizoclonium
Kerneri
Stockm. WILLE
in "Studien uber Chloro-
phyceen",
VII,
p.
41
writes,
as
follows,
concerning the basal rhizoid: >>Beim
Kei-
men der Zoosporen bildet sich ein basales
Endrhizoid
(Taf.
IV,
Fig. 16668); aber
da
sich
die
Faden
durch
intercalare
Teilungen
und
zufallige
Zerreissungen
sehr
stark
vermehren,
so
fmdet
man
Faden
mit
Endrhizoid
sehr
selten.
Inwiefern
die
Faden
urspriing-
lich
festsitzen,
kann
ich
nicht
mit
Sicherheit
ausmachen,
viel-
leicht darf die eigentumliche starke Verdickung an dem
abgebil-
deten Rhizoid (Taf.
IV, Fig.
168) als eine abnorme Entwickelung
gedeutet werden, indem
sie keine Gelegenheit gehabt hatte
sich
zu befestigen, da dieses Exemplar nur loose zwichen den iibrigen
Faden
hing.
Regarding
the
presence
of
basal
rhizoids
in my
specimens no doubt
is
possible. They were vigorously developed
and present in
all the specimens. As the plants have no other rhi-
zoids to
fix themselves with they would immediately have been
washed away by the waves,
if they had not been
fixed by the
basal rhizoids.
The
filaments
increase
by
means
of
intercalary
divisions
of the
cells,
these being divided when they have reached
a
cer-
tain length.
426
The
cells
contain
a very
irregularly shaped chromatophore
of a reticular spongy appearance with smaller and larger openings.
Often
it
fills up the whole lumen
of the
cell so densely that
it is
impossible to see its shape. In the chromatophores a large number
of
pyrenoids
are present,
distributed
regularly
in the
cells. The
cells
contain,
according to
their
size, one
to
four
nuclei.
With
Iodine
and
Chlor-Zinc-Iodine
the
chromatophores
are
coloured
black
showing
that much
starch
is present. With
the
last mentioned chemical the
walls
of the
cells do not show
the cellulose
reaction, the wall, just as when treated with
Iodine
alone,
getting a light yellow tinge.
In
the upper end
of
the
filaments
the
cells
gradually
are
transformed
into
zoosporangia;
the
zoospores
escape
through
an opening in the wall of the cells. In accordance with the descrip-
tion
of WILLE
this
opening
occurs
a
little above
or below the
middle of the cell, and the place, where it will come into existence,
is
beforehand marked by an outgrowth
of the
wall.
To
point
out
any
differences
between
these
affixed
forms
of Rhizodonium,
as
are described above, and
Chsetomorpha seems
nearly
impossible, and STOCKMAYER,
too, has already mentioned
this
difficulty
in his monograph
of the genus Rhizodonium, and
that in
spite
of the
fact that he did not know such forms fixed
by the
original end-rhizoid. Should
I
try to mention some differ-
ences
between
such
forms
of
Rhizodonium,
as
are
mentioned
above,
and
Chsetomorpha
I
think
the most
essential
differences
are,
besides
the
lesser dimension
of the filaments, that the
fila-
ments
of
Rhizodonium
are
mostly
quite
cylindrical,
in
Chseto-
morpha mostly
moniliform,
that
the
cells
of
Rhizodonium
are
mostly
proportionally longer and have
thicker walls than those
of
Chsetomorpha,
that now and then
in
the
filaments
of Rhizo-
donium a thickening of the wall is found round above the
cross-
wall between the
cells
(comp.
Fig. 406 h) while
in
Chsetomorpha
the
filaments
are narrowed
here.
Characteristic
of
* Rhizodonium
is
also a kneelike bending (comp. STOCKMAYER,
fig.
4,
pag.
576)
found now and then in the
filaments. On the whole the appear-
ance
of
a Rhizodonium
filament
is
rather
like
a
Conferva, but
the structure
of the wall is quite
different. Regarding the chrom-
atophore its reticular structure
is more easily seen in Chsetomorpha
than in Rhizodonium in which the dense clumsy-spongy structure
mostly makes
it very
indistinct.
427
The above mentioned
non-colouring
of
the wall of Rhizodo-
nium with Chlor-Zinc-Iodine
is of no use as a means of distinction,
as
the
wall
of
Chsetomorpha,
too,
does
not show
the common
reaction
of
cellulose.
Finally
I agree absolutely with STOCKMAYER when he recom-
mends
to study these
plant upon living material.
Among the fixed forms
I think the two forms mentioned be-
low may be
distinguished.
23.
Rhizocloniuin Kochiaimm
Kiitz.
Fig.
406
,
6,
c, shows
a form
in which the
cells
are from
nearly
as
long as broad up to
2 J
/2 times as long; their diameter
varies from
13
to
20
;JL
in length.
The zoosporangia
are
a
little thicker, about 25 p.
Another form
is figured in
Fig. 406
d,
e,
/,
g.
It
is a
little
thicker than the above described
plant, its vegetative
cells reach-
ing a breadth
of about 20 ^, the length
of
the
cells up to 62 p.
The zoosporangia
are about 35
p.
thick.
St. Jan:
Christiansfort.
24.
Rhizocloniuin
Kerneri Stockm.
Some other of the fixed forms
I prefer to refer to
this
species
which
is characterized by
its somewhat longer
cells.
Fig.
407
a,
6,
c shows one form whose vegetative
cells
are
about
10
fji thick and
40 ^ long.
It is fixed to the rocks by a long
rhizoid formed by throughgrowing
of three
cells.
The zoosporangia are often a
little narrowed in their middle,
about
13 n
thick.
Another form with somewhat
shorter
cells
is figured in Fig.
407
d,
e. The vegetative
cells
are about
12
// broad and two to
four times
as
long.
St. Jan:
Christiansfort.
25.
Cladophora unciuata Bergs.
26.
corallicola
B0rgs.
27.
fuliginosa
Ktitz.
28.
utriculosa
Kiitz.
KUTZING, Phycologia
generalis,
p.
269;
Species
Alg.,
p.
393;
Tabulae
Phycologicae,
vol.
3,
tab.
94,
fig.
1. Hauck,
Meeresalgen.
p.
454.
428
A small tuft of this plant was found in termingled between several
other algae. The cells in the basal part were about 150
(
thick and up
to ten times as long, upwards gradually shorter and thinner, the cells
in the upper ramuli being only about 70,
thick and a few times longer.
Found
in
shallow water, near the shore in a rather unpro-
tected
place.
St. Croix: Coakley Bay.
29.
Cladopkora
fascieularis
( Mert.)
Kiitz.
30.
crispula Vickers.
31.
heteroneina
(Ag.)
Kiitz.
32. Anadyomene
stcllata (Wulf.) Ag.
33.
Microdictyon
uinbilicatum
(Veil.) Zanard.
34.
Valonia
ventricosa
J. Ag.
35.
macrophysa
Kiitz.
36.
utricularis (Roth) Ag.
37.
.Egagropila
C. Ag.
38.
Dictyosphseria favulosa (Ag.) Decsne.
39.
van Bossese
B0rgs.
40.
Cladophoropsis membranacea (Ag.) B0rgs.
41.
Boodlea
Siamensis
Reinb.
42.
Struvea elegans B0rgs.
43.
Struvea anastomosans (Harv.)
Piccone.
44.
Chamsedoris Peuiculuni
(Sol.)
O. Kuntze.
45.
Siphonocladus tropicus (Crouan)
J. Ag.
46.
Ernodesmis
verticillata (Kiitz.) Bergs.
47.
JVeomeris annulata
Dickie.
48.
Batophora
Oerstedi
J. Ag.
49.
Acetabularia
Caliculus Quoi
et Gaimard.
50.
crenulata Lamx.
51.
Acicularia
Schenckii (Mob.) Solms.
52.
Avrainvillea
nigricans Decsne.
53.
Mazei Murray & Boodle.
54.
Geppii B0rgs.
55.
asarifolia B0rgs.
56.
Rhipilia tomentosa
Kiitz
57.
Cladocephalus
luteofiiscus (Crouan) Borgs.
58.
Penicillus capitatus Lamarck.
forma typica.
laxa.
429
59.
Penicillus Lamourouxii
Decaisne.
60.
pyriformis A. and
E.
S. Gepp.
forma typica.
explanata.
61.
dumetosus
Blainville.
62.
Udotea
conglutinata
(Ell. et
Sol.) Lamx.
63.
cyathiformis Decsne.
64.
spinulosa Howe.
65.
occidentalis A. and
E. S. Gepp.
66.
verticillosa A. and E.
S. Gepp.
67.
Flabellum
(Ell. et
Sol.) Howe.
68.
Halimeda Tuna
(Ell. et
Sol.) Lamx.
var.
typica Barton.
var. platydisca (Decsne) Barton.
69.
discoidea
Decsne.
var.
typica Bergs.
In
the
text
p.
106
after
the
word
typica
a",''
through
misprint
has
fallen
out.
I
regret
the
mistake
having
here-
with
seemingly referred
this
variety
to
Dr. Howe.
Comp.
Dr.
Howe's remark regarding
this
matter
in
"Torreya",
vol.
15,
1915
p.
48.
var.
platyloba B0rgs.
70.
Halimeda Opuntia
(L.) Lamx.
71.
gracilis Harv.
var.
opuntioides B0rgs.
72.
incrassata
(Ell.
et
Sol.) Lamx.
var. typica Barton.
f. gracilis
Bergs,
var. monilis
(Ell. et
Sol.) Barton.
f. robusta
B0rgs.
f. cylindrica
Bergs,
var. simulans (Howe)
Bergs.
73.
Codium
difforme
Kiitz.
74.
tomentosum (Huds.) Stackh.
75.
isthmocladum Vickers.
76.
elongatum
C. Ag.
77.
Bryopsis Duchassaingii
J. Ag.
430
78.
Bryopsis plumosa (Huds.) Ag.
var. pennata (Lamx.).
var. secunda Harv.
var. Leprieurii
(Kiitz.).
79.
Caulerpa
fastigiata Mont.
Besides
the
locality
mentioned
above
this
plant
has
been
found among several other
algse on the
reef between the
Hurri-
cane
Island and
St. Thomas.
80.
Caulerpa Vickersiae B0rgs.
Being
dedicated
to
the
late M
llc Vickers
the
specific name
for this plant ought
to be
Vickersiae and not
Vickersii.
81.
Caulerpa
verticillata
J. Ag.
f. typica
Bergs.
f. charoides (Harv.) Web. v. Bosse.
82.
Webbiana Mont.
f. dislicha Web.
v. Bosse.
83.
prolifera
(Forsk.) Lamx.
f. obovata
J. Ag.
f. zosterifolia B0rgs.
84.
crassifolia
(Ag.)
J. Ag.
f. typica (Web.
v.
Bosse) B0rgs.
f. mexicana (Sonder)
J. Ag.
85.
taxifolia (Vahl) Ag.
86.
sertularioides (Gmel.) Howe,
f. typica
B0rgs.
f. brevipes
(J. Ag.)
Svedelius.
f. longiseta
(J. Ag.)
Svedelius.
f. Farlowii (Web. v.
Bosse) B0rgs.
87.
Ashmeadi
Harv.
88.
cupressoides (Vahl) Ag., Web. v. Bosse emend,
var. mamillosa (Mont.) Web. v.
Bosse.
var. typica Web. v.
Bosse.
var. plumarioides B0rgs.
var. flabellata Borgs.
var. elegans (Crouan) Web.
v.
Bosse.
89.
racemosa
(Forsk.) Web. v.
Bosse.
var. clavifera (Turner) Web.
v.
Bosse.
f. reducta B0rgs.
431
var. uvifera (Turner)
J. Ag.
var. occidentalis
(J. Ag.)
B0rgs.
var. Isetevirens (Mont.) Web.
v.
Bosse.
var. Lamourouxii (Turner) Web.
v.
Bosse.
90.
Vaucheria dichotoma
(L.) Ag.
Phaeophyceae.
Pylaiella
(Bory) Kjellmann.
Subgen.
Bachelotia Bornet.
1.
Pylaiella
fulvcscens (Schousb.)
Bornet.
BORNET, ED., Note sur 1'Ectocarpus (Pylaiella) fulvescens Thuret (Revue
generate bot., tome
1,
1889,
p.
5,
pi.
1); Les Algues
de
P.-K.-A. Schousboe
(Memoires... Cherbourg,
t. XXVIII, 1892,
p.
247). SAUVAGEAU,
C., Note sur
1'Ectocarpus
(Pylaiella) fulvescens Thuret (Journ. de Botanique, 1896, p. 47).
Conferva fulvescens Schousboe mscr.; Icon, ined.,
t. 115 in Herb. Thuret.
Ectocarpus fulvcscens Thuret
in Algae Schousb.
no's 109110.
This peculiar plant has been found
twice in two different collections inter-
mingled with other
algse.
As
is well known from BORNET'S
and, more recently, from SAUVAGEAU'S
descriptions of this plant it has creeping
filaments
fixed
to the rocks by short
haptera;
from these creeping filaments
the
erect
ones
arise.
In
the
material
gathered
I have found small fragments
of
the
creeping
filaments,
but
an
abundance of the erect filaments, these
having been cut over when
collected.
In most of the erect filaments an inter-
calary growing zone was found in about
their middle. In this zone the cells are
dark coloured, the chromatophores
fil-
ling up nearly the whole lumen of the
cells; these
are
all short being divided
as soon
as they reach a length
corre-
sponding to their breadth or even earlier,
angia. a, about 150:1 ; b, 70:1.]
p
.
g
40g ^^ fvj/oeseen8
(Schousb.) Bornet.
a, part of
432
From
this
growing
zone
the
cells
gradually
increase
in
length
towards
both
ends. The filaments are about
35
ta
thick and the
cells reach a length of up to
90
fj.. The peripheral walls are about
2
fj.
thick.
In
some
of the filaments
rhizoid-like
short branchlets were
found (408
a). These seem to be able to grow out from
all vegeta-
tive
cells;
in
one
filament,
for instance, they were growing out
from both ends of the filament. Another filament was much curved
in the one end and from nearly all the cells here short branchlets
were issued from the convex
side
of the
filament. According to
Fig. 409.
Pylaiella fulvescens (Schousb.) Bornet.
-
a,
b,
cells with chloroplasts and nuclei,
c,
parts of a
fertile
filament.
(About
350:1.)
SAUVAGEAU
this takes place in the upper ends
of the
erect
fila-
ments, these by means
of these branchlets,
crampons
becoming
often
fixed
also
in
the upper
end. The
branchlets may
attain
to
a
considerable
length; they have more
or
less
sinuate
walls.
They
are
about
16 ^
thick,
their
cells
being
about
four
times
longer than broad.
The
cells contain a beautiful and very characteristic chrom-
atophore,
closely reminding
of
the
one in Zygnema
(Figs. 408 a,
409). The chromatophore
is
stellate;
from
a
dense
centre
long,
thin
prolongations
protrude
in
all
directions
towards
the
wall
of
the
cells,
here
often being broadened
out
to
small
roundish
or oval
discs
lying
closely
against the
wall. Two
stars
of
chro-
matophore are present in each cell; in the longer cells the distance
433
between
the
two
chromatophores
is
often
rather
considerable
these being connected by a broader
or slender strand
of proto-
plasm.
In
the
shorter
cells
the
chromatophores
gradually
ap-
proach forming apparently
in
the young and newly divided
cells
but
a
single
stellate
chromatophore.
As pointed out by SAUVAGEAU, too, the comparatively small
nucleus
is found in the
strand
of
protoplasm
between
the
t\vo
chromatophores (comp.
Fig.
409 a,
b.)
In one
of the filaments nearly
ripe sporangia were
present.
The sporangia have thick walls
(Fig. 409
c); they are somewhat
broader than the
vegetative
cells, about
50
jj.
broad,
but
often
not half as long, about 20
//. In the upper end a few of the
cells
were
divided
into
two
sporangia
each.
In
the
fertile
filament
found,
35 sporangia were present
in the row
(Fig. 408
g).
None of the sporangia present were ripe or emptied, but the
disposition of the very large zoospores, characteristic of this plant,
was
clearly
seen.
According
to
the
above description the West
Indian
plant
seems
in
all
essentials to agree with the one from Morocco and
the South
of France,
described by BORNET and SAUVAGEAU.
It was found with sporangia in the month
of March.
It was once gathered on rocks near the
surface
of the
sea
between
other
small
alga?,
e.
g.
Chaetomorpha, Enteromorpha and
Myxophycese. in a rather exposed place where the waves constantly
dash the rocks. Another time
it was found in a more protected,
lagoon-like
locality
intermingled
with
a
tuft
of Hypnea
cervi-
cornis.
St. Thomas:
near Charlotte Amalia
in
the
Harbour.
St. Jan: Cruz
Bay.
Geogr.
Distrib.: Morocco, south
of France and
Spain.
2. Ectocarpus Duchassaingianus Grun.
3.
Mitchellae Harv.
4.
coniferus Bergs.
5.
Rallsise
Vickers.
6.
rhodockortonoides
B0rgs.
In the
diagnosis
p.
170 the diameter
of the filaments
is, on
account
of
a misprint,
stated
to be 21 ,;
it
is
11 ^
as
is found
in the text,
p.
171, but
this length of the diameter is found only
28
434
in the basal part of the filaments and in the more vigorous ones,
higher up in the filaments and in
the less vigorous the diameter
descreases
to about
7 p.
The chromatophores are not very developed;
each consists of
a few irregularly bent and ramified narrow ribbons in each
cells.
7.
Ectocarpus variabilis Vickers.
VICKERS, A., Liste des algues de la Barbade (Ann.
sc.
nat. Bot.,ser.,9,
t.
5,
1905,
p.
59); Phycol.
Barbadensis,
pi. XXXI.
Upon some
old leaves
of
Thalassia testudinum a small creep-
ing
Ectocarpus was
found
forming small low tufts upon
it. This
plant
I
think
referable
to
the
above
mentioned
species
of
the
late Mile. VICKERS.
In one respect, to be sure namely the length
of
the
cells,
it
differed somewhat from her
figure
in which the
cells
are drawn very
short, mostly not twice
their breadth, but
in the diagnosis
of the species the
length
is said
to be three times the breadth which agrees better
with my
plant.
The
plant,
of which a piece
is shown in Fig.
410, has creeping basal filaments from which the
erect ones
arise. These have a diameter of about
9
12
fj.
in their lower part decreasing gradually
upwards to about 7
j
. In the lower part the cells
are about 22
30
40
/* long, higher up they be-
come
slowly
longer,
in
the
upper
ends
of
the
filaments reaching
a
length
of more than 60
//.
The upper ends
are not
hairlike, the apical
cells
have roundish summit, ending now and then in a
sporangium.
A marked growing zone
is not
found.
In each
cell several irregularly bent, narrow
ribbon-like, chromatophores
are
present.
The
plurilbcular sporangia are sessile or ped-
icellate,
of rather variable
size and shape, lance-
olate
to oblong with
broadly rounded
summit;
about
60 p long and
27 ^
broad.
Fig.
410.
Ecto-
carpus variabliis
Vickers.
(About 250:1.)
The plant was found in a lagoon-like
locality
in
the
harbour of St. Thomas.
Geogr. Distrib.: Barbadoes.
8.
Ectocarpus breviarticnlatus
J. Ag.
9-
elachistsBforinis Heydr.
Of
this plant
I have come
across some
more material, and
I am able to make some
additions
to my
former
description,
vol.
I,
p.
174.
In
its
basal
part
not
only
horizontal
filaments are present, as shown in Fig. 137
,
but
also more or less vertical short ones (Fig.
411
a). These are growing down in the
tissue
of
the
host.
They
are mostly
rather
thick,
about
20
in thick and composed of short cells
in which chromatophores
are
present.
The upper
cells of the
assimilating
fila-
ments
are
often
nearly
colourless,
but their
summits
are
mostly obtuse.
The uppermost
cells reach
a length
of about
70
//.
Upon the assimilating filaments from near
their
base
and rather
high
up ;
short
pluri-
locular sporangia occurred
(411
b).
These are
mostly short, proportionally thick and
sessile,
they
are
about
12 ^
broad
and
25
35 up
to
70
//
long.
The common plurilocular sporangia, found
at
the
base
of
the
plant,
often
reached
a
length
of more than 170 //.
In one
plant a supposed unilocular spor-
angium was found
(Fig. 411
b).
It was ovate
of shape, placed terminally upon a short stalk
composed of short
cells. The sporangium was
50
fj. long
and
28
^i broad
;
the
cells
in
the
stalk
11
fi broad.
Fig.
411.
Ectocarpus
elachistse-
formis Heydr.
a, part
of the base of a plant.
b,
part of plant with
unilocular
sporangi-
um
and
plurilocular
sporangia
up
along
the
assimilating
fil-
ament.
(a,
about
200:1;
b,
150:1.)
AsCOCyclus
Magnus.
10.
Ascoeyclus Hypnese nov. spec.
Fila
basalia
endophytica
inter
cellulas
externas
hospitis,
Hypnese,
musciformis,
repentia,
ex
cellulis
brevibus
cornposita;
28*
436
heec
pilos, ascocystos et sporangia erecta extra hospitem surgentia
gignunt.
Ascocysti
clavati,
ca. 65 n longi
et 10
16
//
lati.
Pili longi;
articuli eorum
in
parte
basali
breves,
ca.
6
p.
lati,
in
superiori
parte longi,
ca. 180 ^
et crassiores,
ca. 16 ^ lati. Sporangia pluri-
locularia
ex
pediculis
brevibus
surgentia,
oblonga-fusiformia,
ca.
16
26 p
lata
et
65
/./
longa.
Upon
a specimen
of Hypnea musciformis a small,
partly
en-
dophytic
brown alga was
found
which
I
think
can
be
referred
to the genus Ascocyc-
lus, having
those
bo-
dies, named
ascocysts
by Sauvageau (Myrio-
nemacea3, p. 9), chara-
teristic of the genus
The
base
of
the
plant
(Fig.
412
a,
b]
consists
of
filaments
creeping
among
the
peripheral
cells
of the
Hypnea.
The
cells
in
these
filaments
are
Fig.
412.
Ascocyclus Hypnese nov.
spec.
rflthprirrPOMilftrlvslian
a,
b,
c,
parts of the plant.
(About 150:1.)
rather irregulaily shap-
ed,
often
swollen
in
their middle.
They reach a breadth
of about
7
8 //. From these
cells
arise:
1)
the
ascocysts,
2) the
hairs and
3) the
sporangia.
Characteristic
for
all
three
organs
is
that they
are
rather
thin
at their start from the creeping filaments, but gradually, as they
approach the
periphery
of the
host
plant, they become
thicker
(comp.
Fig.
412).
The
ascocysts
are
clavate
in
shape;
from
a
slender
base
they
increase
gradually upwards
until
near
their
apices
which
are broadly rounded. They are about 65 n long and their diameter
reaches a length of about 10
16
//. They may arise directly from
a
cell in the creeping filament
or have a few short
cells
at their
base. They have thick walls and their contents seem rather homo-
genuous and of a dark brown colour in spite of the plant having
been preserved
in
alcohol.
The hairs have a growth zone near their base; here the cells
437
are
quite
short
and
filled
with
chromatophores
;
higher
up
the
cells gradually grow longer and become nearly destitute of chro-
matophores; in the upper parts of the hairs the cells reach a length
of about 180
IJL. In the basal part the hairs are thin, their diameter
reaching
a length
of about
6 p
only;
higher up
the
hairs grow
thicker
to about
16
p. The
cells
of the
hairs
are
barrel-shaped
cylindrical,
being
a
little narrowed
at the
cross-walls.
The
plurilocular
sporangia
are
oblong
to
spindleshaped,
about
16
26 ^ broad and
65
IJL
long. They have
a
short
stalk
consisting of a
single
or a few
cells.
Owing to its partly endophytic way of growing and to the fact
that
the
basal
filaments
do
not
form
a
disc
this
plant
differs
from
the
hitherto
described
species
of
this
genus
and
ought
perhaps rather to be referred to a new genus. Nevertheless
I have
preferred
to
refer
it
to
the
genus
Ascocyclus,
having
not
seen
much
of
it.
The Hypnea upon which
this plant was found was gathered
in the month
of January near the shore
in shallow water.
St. Croix: Lime Tree Bay.
Fam
. Myriotrichiacece*
Myriotrichia
Harv.
11.
Myriotrichia
occidentalis nov. spec.
Frons
ex
filis
basalibus
repentibus,
ramosis
et
filis
erectis
composita.
Filamenta basalia ex
cellulis, 20
/* longis et 10 p latis compo-
sita, ramis aut
oppositis aut
alternis
et
unilateralibus
instructa.
Ex
cellulis
basalibus
aut
pili,
aut
fila
brevia,
aut
rarius
sporangia
plurilocularia aut filamenta
principalia oriuntur.
Pili
ca.
12
JJL
lati
ex
cellulis
hyalinis valde
elongatis
orti.
Fila brevia,
ca. 150
/-/
alta et 12
fj.
lata, ex cellulis ca.
6 com-
posita,
apice
obtuso,
rarius ramosa.
Fila
principalia
monosiphonia,
ca.
1 mm
longa, 1824
//
lata;
ha3C
ex
cellulis
sparsis (nodis)
fila
brevia,
simplicia
aut
ramosa,
opposite aut
subverticillate orta gerunt.
Sporangia
plurilocularia,
aut
sessilia
aut
pedicellata,
50-
100
rj. longa et 12
30 p
lata ex seriebus pluribus loculorum com-
posita.
438
The plant (Fig. 413) forms small, low tufts upon the host plant,
Dictyota
indica, from which
the
longer main filaments protrude.
The
base
(Fig.
414
a)
of the
plant
consists
of
freely
ramified
filaments
creeping upon the surface
of the host and fixed to it by means
of
quite
short,
small
rhizoids
(Fig.
414
b).
The
filaments
have
apical
growth and the branches are given
off from the distal end
of the
cells
at both
sides, now alternating, now
opposite
or
sometimes,
too,
unila-
teral.
The
filaments
are
mutually
free. The cells in the basal filaments
contain
well
developed
chromato-
phores; the cells are about 10 (J broad
and
20
jii long.
From the
cells
of this base the
different erect organs are given off,
namely: short branchlets, hairs, long
main
filaments
and
more
rarely
plurilocular
sporangia
(comp.
Fig.
413
a
and
414
a,
b).
The
short
branchlets are commonly unbranch-
ed,
nearly
cylindrical with
obtuse
apex, composed
of
about
six
cells
reaching
a
height
of
about
150
u.
and
a breadth of
12 //, more rarely
ramified.
The hairs have one or two basal
cells
of which
the lowermost is the
longest ; above these cells the growth
zone
follows. Upwards in the
hairs
the
cells
rapidly increase in length,
being very
long in the upper end.
The hairs
are about
12
|u thick.
The few
plurilocular sporangia found growing out from the
basal filaments had,
at their base,
a
single or a few
sterile
cells,
about
8
9
u. broad. The sporangia are elongated-spindle-shaped,
about
80
u long and
20
u broad.
Fig. 413. Myriotrichia occidentalis
nov. spec, a part of a, plant with
sporangia
(someones
emptied).
b, apex
of a filament with
ter-
minal
hair.
(a.
about
150:1;
b, about
250:1.)
439
Of
the
long main
filaments
I have found only a
few; one
of the longest, reaching a length of about
1 mm, is figured in Fig.
413. The breadth
of the main filaments
is about 1824
ja; they
are composed of cells of rather variable length from shorter than
the length to about their double length. The filaments found by
me have
all been monosiphonous throughout,
longitudinal
walls
being not
present
at
all. But having seen
so few erect filaments
Fig.
414.
Myriotrichia occidentalis nov.
spec.
a and
b, parts
of the basal filaments seen from above and from the side.
c, part of a main filament with
hairs, branchlets and sporangia.
(a, about 260:1.
b and
c, about
150:1.)
it
is
of
course
possible
that
such may
occur
in
more
devel-
oped
specimens.
As pointed
out by KUCKUCK
]
) the
growth
of
the
main
filaments
takes
place by means
of
intercalary
divi-
sion
of the
cells (comp.
Fig.
413 and 414
c), but this division
is
restricted mostly to the middle and upper end
of the
filaments.
The top of the filaments end in a terminal hair (comp. Fig. 413 b
and
a the branch
to the
right).
The
erect main
filaments
are
provided
with
side-organs
of
*) KUCKUCK, P., Die Gattung Myriotrichia Harvey. Beitrage zur Kenntnis
der Meeresalgen,
6,
1899,
p.
59.
440
three
kinds:
short
branchlets,
hairs
and
sporangia.
They
are
mostly arranged
in a
tier-like manner
issuing
several
from
the
same
cell,
each
tier being separated by a row
of bare
cells.
The branchlets
are
short,
often
spinelike, undivided
or
pro-
vided with
hairs. Two
opposite
branchlets
are mostly given
off
from
each
point.
In
the
upper, more
richly
developed
part
of
the
erect
shoots
the
branchlets
grow
larger,
become
ramified
and bear often
several
plurilocular sporangia and
hairs.
The
hairs
are
like
those
issued
from
the
basal
filaments;
they have a longer cell at their base, then the growing zone follows
above which the cells quickly grow long and colourless. In the lower
part of the erect shoots they are given
off immediately from the
main
filament, higher up,
as mentioned
above, mostly from the
branchlets.
The
plurilocular
sporangia
are
rarely
sessile,
mostly
pedi-
cellate
or
placed upon
the
branchlets. They
are
spindleshaped
about 50100
|u long and 122030
|a broad.
Unilocular sporangia were not found.
Considering
the
species
of
Myriotrichia
hitherto
described
this plant seems to be most closely related to Myriotrichia repens,
this
species having
for the most
part monosiphonous
filaments,
and the dimensions
of the
cells and the development of the erect
filaments being rather like the West Indian plant. But the West
Indian
plant
differs
nevertheless
essentially
from
Myriotrichia
repens
in
the very
different development
of the basal
filaments,
and
in
the
fact
that
the
filaments,
as
far
as
hitherto
found,
always
are monosiphonous, the
knot-cells (Knoten
of KUCKUCK)
being
not
even
divided
and
in
the
development
of
the
pluri-
locular
sporangia,
these
having
two
or more
rows
of
loculi
in
each.
Our plant seems to show some likeness, too, to the certainly
very
imperfectly
known
species
Myr.
canariensis
Kiitz.,
but
this
species
has
rather many
longitudinal
walls
in
the
main
filaments,
and
the
plurilocular
sporangia
seem,
according
to
KUTZING'S
figure and
as
pointed
out by KUCKUCK,
to be very
like those found
in M.
clavaeformis.
The
Dictyota
indica upon which
this species was found was
dredged
in the month
of February in the open sea at a depth of
about ten meters.
St. Croix:
of! Frederikssted.
441
12. Colpomenia
sinuosa (Roth) Derb. et Sol.
13.
Hydroclathrus
cancellatus Bory.
14. Rosenvingea
Sanctse
Crucis
Bergs.
In the description
of this
plant
(vol.
I,
p.
178) the
locality
and occurrence has been omitted.
It was found
in shallow water
near the shore in a sheltered place this being protected from the
open sea by coral
reefs.
It was attached to small
stones.
It was
gathered
in the month
of January.
St. Croix: Longford.
15.
Castagnea
Zosterae (Mohr) Thur.
16. Myrionema vulgare Thur.
THURET,
G.,
in Le Jolis,
Liste des algues mar. de Cherbourg, p.
82.
SAUVAGEAU,
C., Sur
quelques Myrionemacees
(Ann.
sc.
nat.,
Bot.,
Ser.
8,
Tome
5,
1897,
p.
185).
Upon
an
old
Sargassum,
together
with many
other
epi-
phytic and
partly endophytic
algee,
a
Myrionema
also occurred
which
I
think
referable
to M. vulgare.
Fig.
415 a shows
a
part of the basal
disc;
it
consists
of
creeping
fil-
aments
whose
cells
are
from 5 to
7
ja thick. And
fig.
415
b
shows
pluri-
locular
sporangia
from
the
older
parts
of
the
plant;
the sporangia are
about 7
(a thick. The hairs
have a rather long sheath
at
their
base;
they
are
about
7
8
|ii thick.
This plant was found
Fig.
415. Myrionema vulgare Thur.
a,
b,
c, parts
of
a
plant from
St.
Thomas.
d, part of a plant from
St. Croix.
e, part of
a plant from
St.
Jan. (a, b, c, d, about 275: 1.
e, about
200:1.)
in
the
harbour
of
St.
Thomas.
A very similar plant
was found upon Chaetomorpha antennina gathered at
Northside,
St. Croix in a very exposed place
(Fig. 415
d).
442
Further upon an old Dasya a tuft of a somewhat more robust
form was found
(Fig.
415
e).
The base
of this plant was very like the Fig. 2A
of SAUVA-
GEAU,
1.
c., p. 31. The cells in the filament are about 8
10
ja thick.
Hairs
occur
rather abundantly; they have
a
growing
zone
at
their
base with
a
slightly
developed
sheath
and
are
about
7
8
;a
thick. The
erect
assimilating
filaments
consist
of about
4
cells;
their diameter reaches a length
of about
11
jn. Of
pluri-
locular sporangia only a few unripe have been found. This plant
was dredged in about ten fathoms of water in the sound between
St. Thomas and
St.
Jan:
off Cruz Bay.
Geogr. Distrib.: The European and American shores of the Atlantic
Ocean, Mediterranean
Sea.
17.
Ralfsia expansa
J. Ag.
18.
Lithodernia
spec.
19.
Aglaozonia
Canariensis Sauvag.
20.
Sphacelaria
tribuloides Menegh.
21.
furcigera
Kiitz.
22.
Zonaria
variegata (Lamx.) Mert.
23.
lobata Ag.
24. Padina
Sanctse
Crucis B0rgs.
25.
gymnospora
(Kiitz.)
Vickers.
26.
Howeana nov. nom.
Syn.:
Padina
variegata Hauck
et
auctores.
HAUCK,
F., Ueber
einige
von
I. M. HILDEBRANDT im Rothen Meere und Indischen Ocean gesammelte
Algen (Hedwigia, vol.
26, 1887, p.
41). VICKERS, A., Phycologia Barbadensis.
part II,
pi. VIII. BORGESEN, F., The marine Algae of the Danish West Indies,
vol.
I,
p.
205. COLLINS. FR.
S. and HERVEY, A. B., The Algse
of Bermuda,
v.
87.
Zonaria variegata
Kiitz., Tab.
Phyc.,
vol.
IX,
pi.
73,
fig.
2.
In a review of the parts of my paper dealing with the green
and brown
alga? Dr. HowE 1
) points out that when both Zonaria
variegata
and
Padina
variegata
are derived
from LAMOUROUX'S
Dictyota
variegata
this
practice cannot be kept up
according
to
the
rules
of nomenclature.
Dr. HOWE
writes:
This
practice,
which
did
not
originate
with
BORGESEN,
seems
to
rest upon
the
assumption
that
the
original Dictyota variegata
of LAMOUROUX was a mixture
of two
l
)
In
Torreya,
vol.
15,
1915,
p.
46.
443
species,
representing two
genera
of
the same
family, and
that,
in
spite
of the confusion
entailed,
this
specific name was
av,i li-
able and valid in each of these two related genera,
-
- a practice
that
is
possibly permissible under the
Vienna Rules
but is dis-
tinctly
forbidden
by
the
"American
Code.
In
this
particular
case,
the
present
reviewer
has
enjoyed
the
privilege
of
seeing
the
specimens
of
Dictyota
variegata
Lamour.
in
LAMOUROUX'S
herbarium
at Caen and
finds
that they
agree
with
the
figures
published by LAMOUROUX in showing only a Zonaria (the Gymno-
sorus variegatus
of
J. AGARDH),
so that the name
Padina
varie-
gata (Lamx.) Hauck, employed by BORGESEN would seem to be
vulnerable on the ground of historical fact as well as on the ground
of nomenclature theory.
To this
I wish to remark that, when working out my paper,
I had no access to the original specimens of LAMOUROUX, the ex-
amination of which was the necessary starting point for an even-
tual change of name for one of the plants in question, the figure
of LAMOUROUX being such, that even if it shows perhaps most like-
ness to Zonaria variegata this, nevertheless, cannot be stated with
absolute
certainty.
Therefore
I
followed
the practice
of HAUCK.
But now, when
Dr. HOWE
has examined the
original specimens
of LAMOUROUX, the
case
is
different. The
plant, named Padina
variegata
uptill now, must be given a new
specific name and
in
honour
of
Dr.
HOWE, who
has
solved
the question,
I
propose
to
call
it Padina Howeana.
27.
Dictyota Bartayresiana Lamx.
28.
linearis (Ag.) Grev.
29.
volubilis
Kiitz.
30.
pardalis
Kiitz.
31.
Indica Sender.
32.
ciliata
J. Ag.
33.
crenulata
J. Ag.
34.
dentata Lamx.
35.
Dilophus
alternaus
J. Ag.
36.
(xiiineensis
(Kiitz.)
J. Ag.
37.
Dictyopteris delicatula Lamx.
38.
plagiogramma (Mont.)
Nickers.
39.
Justii Lamx.
444
Dictyerpa
Collins.
40.
Dictyerpa Jamaicensis
Collins.
COLLINS,
F.
S.,- The
algae of Jamaica (Proceed. Americ. Acad.
of Arts
and
Sciences,
vol.
37,
1901,
p.
251).
Some
small specimens have been found which
I think
refer-
able to this plant. They were collected in a rather exposed place
upon the small reef near the entrance to the harbour of St. Tho-
mas. They form small, low tufts, most probably growing in nar-
row crevices in the rocks over which the waves constantly dashed.
They
are
fixed
to
the
substratum by means
of numerous
rhi-
zoids breaking out
in groups everywhere on the
thallus.
The
thallus
consists
of thin
slender
filaments about
300
to
600
LI thick or more, which, in
transverse section, are roundish or
oval. The ramification
is very irregular, being
di,
tri- to polychoto-
mous. The
internodes
are
of
variable
length;
they
are
thinnest
at their base and
increase gradually upwards. The young group
of rhizoids are covered by the cuticula forming an indusium which
bursts later on. The rhizoids
are about 27
LI thick, being divided
into
cells more than four times longer.
The;y
are irregularly bent
and
nearly
destitute
of contents.
The
thallus increases by means
of
a
large nearly hemisphe-
rical apical
cell from which segments are cut
off in
all directions.
From
a transverse
section
is
seen
that
the
thallus
consists
of a
cortical layer
of
small,
nearly quadrangular
cells with con-
siderable
contents
and
a
medullary
layer
of
larger
colourless
cells
being
irregularly
polygonal
or
often
nearly
rectangular;
the walls of these cells are more or less undulated. A longitudinal
section shows these
cells to be about twice
as long
as broad.
Regeneration seems to take place very
easily,
I have several
times seen a group
of young branches grow out from the thallus
when
it has been broken.
As in the case of the plant from Jamaica this, too, was quite
sterile.
Regarding
this
plant
SVEDELIUS
in
ENGLER
u.
PRANTL,
Nat. Pflanzenfam.. Nachtr. zu
1. Theil, Abt.
2,
p.
188 writes: Die
Gattung
Dictyerpa
1st
hochst
wahrscheinlich
nichts
anderes
als
eine
freiliegende,
trotzdem
aber
weiterlebende Form
einer
nor-
malerweise
auf
Steinen
wachsenden
Dictyota,
die
durch
die
445
t'reiliegende
Lebensweise
ein
Aussehen
und einen
cylindrischen
Ban bekommen
hat,
ganz
wie
z.
B.
freiliegende
kleine
Fucus-
Formen. Daraus
erklart
sich auch ihre
Sterilitat. Most probably
SVEDELIUS
is right in this supposition. To be sure my plant was
not
detached,
but
fixed
to
rocks.
Nevertheless
there
is a
possi-
bility that we may have to do with a form, the development
of
which
has been
retarded
because
of
unfortunate,
external con-
ditions
of
life.
It might perhaps belong to Padina, the basal part
of which
in the young
state
is
terete.
Found
in
crevices
in
the small
reef near the entrance to the Harbour
of St. Thomas.
Geogr.
Distrib.: Jamaica.
41.
Turbinaria
trialata
Kiitz.
42.
Sargassum vulgare
C. Ag.
var.
typica.
var.
foliosum (Lamx.)
J. Ag.
43.
Icudigerum
(L.)
Kiitz.
44.
platycarpum Mont.
45.
Hystrix
J. Ag.
1
)
Rhodophyceae.
1.
Asterocytis raniosa (Thwaites) Gobi.
2. Gomotrichum
elegans (Chauv.) Le
Jolis.
3.
Humphrey!
Collins.
As already pointed out
in a corrective note
to
the Part
II,
1916, of the Rhodophyceae, the plant which
I, on p. 10, have referred
to Bangiopsis subsimplex is not this plant, but a form of COLLINS'
Sargassum
natans
(L.)
Meyen
and
Sargassum
fluitans
Borgs.
both
treated
in
length
in my
paper:
"The Species
of
Sargassum
found
along
the
coasts
of
the Danish West
Indies with
remarks upon the
floating
forms of the Sargasso Sea"
(Mindeskrift for JAPE-ITS STEE.N-
STRUP,
Kobenhavn
1914, No.
32),
and
the
last
species
described
in
vol.
I.
of the present work
p.
222, are both floating, pelagic forms, the
most common species
of the Sargasso
Sea. Now and then both forms
are washed ashore
at
the
islands, but
having
never
been found
at-
tached
there,
they do not belong
to
the
flora
of
the
islands and
are
thereto re not mentioned
in the
list.
446
Goniotrichum Humphrey i,
described
in
COLLINS,
HOLDEN
and
SETCIIELL,
Phycotheca Bor.-Am.,
No.
421 and
in COLLINS, The
Alga?
of Jamaica
(Proc. Amer.
Acad.,
vol.
37,
1901,
p.
251).
4.
Erythrotrichia
carnea
(Dillw.)
J. Ag.
5.
Erythrocladia
subintegra Rosenv.
6.
AcrochaBtium
Sargassi Bergs.
7.
crassipes Bergs.
8.
pulchellum Bergs.
9.
netrocarpum Bergs.
10.
gracile Bergs.
11.
caBspitifornie nov.
spec.
Thallus
parvus,
gracillimus cgespitosus usque ad 700
fJ- altus
in
Padina Howeana
epiphyticus.
Pars
basalis
e
filis repentibus
plus
minus
lateraliter
confluentibus
composita.
Cellulee
sub-
breves,
8
iJ-
longa?
et
5
f*
latse.
Fila
erecta
quoquoversum
ramosa,
ad
apicem
versus
atte-
nuata; ramis
sparsis nonnumquam
secundatis
aut
irregulariter
ortis. CeUulis in inferiori parte filorum ca. 5 p latis et 12
// longis,
in
superiori
ca.
2,5/*
latis;
in ramis paulo minoribus, inferioribus
3
4
fj.
latis,
superioribus
ca.
2
/-/
latis.
Kami
recti,
sub
angulis
acutis surgentes;
in
inferiori
parte
eorum ramuli breves sporangia gerentes.
Sporangia
pedicellata
aut
raro
sessilia,
11
12
//
longa
et
6
fjL
lata.
Chromatophorum
parietale
irregulariter
lobatum
aut
per-
foratum pyrenoide
laterali munitum.
Upon a young Padina Howeana an Acrochastium was found
which
I think must be regarded
as
a new
species
(Fig.
416).
It
comes, undoubtedly,
in
several
respects rather near to the
Acr.
gracile described above on
p.
26, but
differs from
this
species
in
its
ramification
and
in
the
deviating
arrangement
of the
spor-
angia.
The plant forms small roundish tufts formed by the densely
placed
and
very
ramified
filaments.
It
grows
with
preference
along the edges of the Padina and the basal filaments run along
it. The base (Fig. 416 a), in which the original spore
is not visible,
consists
of filaments creeping upon the surface of the host. These
filaments merge more
or
less
together, forming
an
often
large,
447
more
or
less coherent
disc. The
cells
in the basal
filaments
are
about
5
fj. broad and
8
a
long.
From nearly
all the
cells
of these filaments erect ones
arise.
These
are ramified from rather near the base;
the branches
are
given off in all directions, but very irregularly, often several above
each other at the same
side. And the distance between the bran-
ches,
too,
is
very
vari-
able; in some cases a row
of
cells
of the main
fil-
aments
carry
a
branch,
in other several bare cells
are present between those
bearing
branches
(Fig.
416 b}. The branches are
straight and given
off at
acute
angles.
The main
filaments are at the base
about 5 p
thick and the
cells 12 n long; upwards
they
taper
slowly
to
about 2,5//. The branches
are
proportionally smal-
ler, 3
4 ^
at
their base,
about
2
fjt
at
their sum-
mit.
The
sporangia
are
linear-oblong,
11
12
//
long and about 6 p broad.
They
occur upon
short
branchlets
at
the
base
of the branches (Fig. 416
b,
c). The sporangia
are mostly
pedicellate, rarely
sessile.
In tho
upper end of the main filaments these, too, carry branchlets with
sporangia.
The
chromatophore
is
an
irregularly
lobed
or
perforated,
parietal
plate, covering most
of the
cell and including a
lateral
pyrenoid.
The
most
important
differences
between
this
species
and
Acr. gracile
are, that
in
Acr.
gracile the
erect filaments
are very
Fig. 416. Acrochsetium csespitiforme nov. spec.
a, basal part
of the plant,
b, upper part
of
a filament,
c, branchlet with
sporangia.
(a, about 200:1;
b, about 260:1;
c, about
600:1).
448
slightly ramified or not
at
all, while in Acrochsetium cssspitiformis
the
ramification
is
considerable;
further,
the
sporangia
in
Acr.
gracile,
owing
to
the
scanty
ramification,
are
placed up
along
the main filaments, while in Acr. csespitiforme
they
are found
at the base of the branches.
The
plant was gathered
at
the end
of
February in
shallow water near the
shore.
St. Croix:
Salt River.
12.
Acrochsetium globosum
Bergs.
13.
Sancti Thoinae
Bergs.
14.
seriatum Bergs.
15.
flexuosum Vickers.
16.
Acrochaetiuin spec.
Upon
a young Padina Howeana a few
plants of an Acrochsetium were found, show-
ing apparently some
likeness
to Acr. flexuo-
sum.
Having had so
little material of it
at
my disposal,
I
prefer to
leave
it unnamed.
It
forms
tufts
up
to
more than one
mm.; one specimens was about 1200// high.
The
base
consists
of
short,
creeping
filaments
(Fig. 417 a);
these are irregularly
bent, in the middle of the basal layer inter-
woven and merging together, but with
free
ends. The
cells
in
the
basal
filaments
are
about
8
fj. thick and
11
fj.
long.
The
erect
filaments (Fig. 417 b) arising
from the
basal
filaments are from 10
13
fj.
thick and the cells about 35 n long. Upwards
the main filaments do not taper much
: until
at about
8
11
//.
The
filaments
are very ramified;
from
near
the
base
they
carry branches
given
off
irregularly at
all
sides with
longer
and
shorter rows
of bare
cells
in between, and
often with some
ten-
dency
to
secund
arangement.
The
branches
are
given
off
at
acute angles; they seremto be rather rigid and are a little curved.
They
are somewhat
thinner than
the main
filaments,
at
their
base about
9
/^, tapering to -about
5
to
6
p.
at
their apex.
Fig.
417.
Acrochsetium
spec,
a,
base
of
the
plant,
b, part of
erect
filament.
(a, about
200:1; b, about 150:1).
449
The chromatophore
is
a
parietal
plate with
a
large
lateral
pyrenoid, protruding
far into the lumen
of the
cell.
The sporangia occur
at the base of the branches; in the spe-
cimens found
one, two,
or, more
rarely, three upon each branch,
The
sporangia
are
pedicellate
or
more
rarely
the
uppermost
sessile. The sporangia are oval in shape; they have a thick wall
especially at their upper end. They are about 21
// long and 13 n
broad.
From
this
plant
Acr.
flexuosum
Vickers
chiefly
differs
in
its thinner filaments and by the presence
of ramuli, upon which
the sporangia are
placed.
Our
plant
ought
also
to
be
compared
with
Acr.
Daviesii
(Dillw.)
Nagl.
showing in
its
short, thick-walled
cells and whole
ramification great
likeness
to
this
species.
But
it
differs
in
an
essential way especially by the lack of
the repeatedly
ramified
branchlets.
The plant was gathered in shallow water
at the end
of Fe-
bruary.
St. Croix:
Salt River.
17.
Acrochsetium
unipes B0rgs.
18.
opetigenum B0rgs.
19.
Acrochsetium robustum Bergs.
When
I
described
this
plant
I had not come across young
specimens. In fig. 418 the basal parts of two young plants are figured
;
in these the basal
discs are not yet
developed.
From
these
figures
it
seems quite clear, that the germinat-
ing spore during its growth produces
downwards the process which pene-
trates
into
the
tissue
of
the
host.
The
process has an acute base and
thick walls. It is not separated from
the
original
germinating
spore by
any
wall.
The
process
is
the only
endophytic part of the plant; the ori-
ginal spore and the small disc gradual-
ly developed round
it are epiphytic.
Fig.
418.
Acrochsetium robustum
Borgs. Bases of two young plants.
(About 250:1).
29
450
Fig.
419.
Acrochsetium spec.
a and
b,
basal
parts
of
plants,
c, upper part of a filament, d, small
part of the same, more magnified.
(a, b, d, about 200:1
; c, about 140:1).
20.
Acrochsetium
spec.
HOWE
anf
HoYT 1
)
in
1916
described
an
Acrochsetium
affine
which is closely related to COLLINS'
ACT,
Hoytii,
described
in
"Rho-
dora",
1908,
p.
134
and
to
the
two
species
Acr.
robustum
and
unipes
described
by
me.
They
made
a thorough comparison
be-
tween
their new species and COL-
LINS' and my plants and
arrived
at
the
conclusion
that:
"there
seems
to be no compelling reason
for
the
association
of
our
plant
with any one
of the
three names
mentioned
rather
than
with
any
other
of the three."
Growing
rather
abundantly
upon
a
Dictyota, which
I
have
determined
to
be Dictyota
indica,
I have once more found an Acro-
chdstium (Fig. 419) which
is closely
related
to
the
above-mentioned
species,
but
which,
nevertheless,
when
more
carefully
examined,
shows
differences
from
all
four
species.
As
is
characteristic
of
these
species
the
germinating
spore
of
the
plant now found
produces
a
more
or
less obtuse process pene-
trating into the peripheral layer of
the host, reaching a length of about
28 ft (Fig. 419
,
ft); the spore itself
remains lying upon the wall of the
host;
its diameter reaches a maxi-
mum of about 16
.
HOWE, M. A. and W. D. HOYT, Notes on some marine Algae from the
vicinity
of
Beaufort, North Carolina (Memoirs
of the New York Bot.
Garden,
6,
1916).
451
From the
spore
a
few
cells
are
gradually developed
in
all
directions; by more or less growing together they form in
older,
vigorous
plants a small
disc. From the spore and from the
sur-
rounding
cells
erect
filaments
are
given
off.
These
are
mostly
not ramified near their base, higher up branches are given
off in
all
directions.
At the base the
filaments
are
8
10
12 p broad,
tapering
slowly upwards, the
apices reaching a breadth
of about
4
6
[j.
only. The filaments reach a height of about 3 mm. The cells contain
a parietal,
slightly developed chromatophore with
a lateral pyre-
noid protruding
far into the
cells. The chromatophore
is mostly
developed in the basal part of the plant, upwards less so. The bran-
ches are given
off at acute angles in
all direction from the main
filaments which are
for the most part easily observable; the bran-
ches
are
similar
to
the main
filaments,
thicker
below,
thinner
upwards. At their base from the distal end of the lowermost
cells
the sporangia
are
issued
(Fig.
419
c).
These
are
sessile
or
pedi-
cellate,
in some
specimens
about
half
of
all
the
sporangia
are
pedicellate.
The sporangia
have
a
little
thickening
of
the
wall
in their upper end (Fig.
419 d). They are about
11
12
ju broad
and
21
/*
long. Other
fructiferous organs were not
found.
If we now compare
this
plant
with
the
above-mentioned
four related species and begin with ACT. unipes we find, that this
species
differs firstly by the fact that generally a single erect
fila-
ment is issued from each spore ; now and then an accessoric branch
may be
present,
but
this
is
no
doubt
mostly
due
to
the
fact
that the primary branch has been damaged; comp. my
fig.
33 b.
The
sporangia seem always
to be
sessile in Acr. unipes, and they
are more
scattered
placed upon the
branches;
furthermore
the
sporangia are proportionally a little broader in Acr. unipes, namely
about
12
[j. broad
and
20 /^ long, and
their apex
is more obtuse
with no such marked thickening above
in the wall.
According
to
HOWE'S
and
HOYT'S
description
Acr.
affine
differs
from
our
plant
on
account
of
the
1
4
erect
filaments
issuing from
the primary
basal
cell,
"often subdichotomous
or
subtrichotomous
at
the
distal
end
of the
first
cell";
further-
more by the
presence
of terminal
hairs.
Cystocarps and
anthe-
ridia were found in
this
plant.
And
Acr.
robustum
differs
from
the
above
described
form
29*
452
by
its much more robust
habit, forming a dense
tuft composed
in
older
plants
of many more
filaments
arising from
the
basal
disc.
The
erect
filaments
are
furthermore
divided
from
near
their
base.
The chromatophore
is vigorously developed, forming
irregularly shaped plates. The filaments are 7
10 p. thick, tapering
very
slightly
from
the
base
upwards,
their
upper
ends
being
5
6
fj. thick with obtuse
apices and with well developed chrom-
atophores,
even
in
the
upper
cells. The
sporangia
are
smaller,
about
9 p. broad and 15^
long.
Finally Acr. Hoytii, according
to the description by COLLINS
and
additional
remarks by HOWE and HOYT,
1.
c.,
p.
119,
differs
from
our
plant by its, on the whole,
smaller
dimensions, by
its
differing
ramification,
the
erect
filament
being much
rami-
fied
below,
rarer
above,
and
by
its
smaller
sporangia
6 X
15
p..
The
Acrochsetiiim
spec, was
found
at
a depth
of about ten
meters.
St. Croix:
off Frederikssted.
21.
Acrochaetiimi bisporuin Borgs.
22.
occidentale B0rgs.
23.
comptuui Borgs.
24.
Avrainvillese B0rgs.
25.
hormorhizum B0rgs.
26.
Hypnese Bergs.
27.
repens B0rgs.
The host plant
in which this
species was
found was Hypnea
musciformis.
Creeping with
its basal part in the thick membrane
of Grif-
fithsia
globifera
an
Acrochxtium was
found
which
I
prefer
to
consider
as
a form
of
this
species,
until
more
material can be
examined.
The plant (Fig. 420) has long, irregularly ramified, endophytic
filaments
creeping
throughout
the
thick membrane
of the host
(Fig. 420 a). Now and then from these basal filaments erect ones
are given
off. The
cells
of the basal filaments
are
subcylindrical
to oval being thickest in their middle, the filaments by this get-
ting a more or less moniliform appearance ; the cells reach a breadth
of up to
11
p. and
are two to three times
as
long. They have a
parietal
chromatophore
with
a
parietal
pyrenoid.
I
have
not
453
been able to discover the original germinating spore and the plant
may therefore be
referred
to group
III
of BoRNET 1
).
The
erect
filaments
have
at
their
base
rather
short
cells;
higher up these grow gradually longer,
the* filaments at the same
time becoming thinner.
At the base of the fila-
ments
the
cells
are
about 8//, in their midd-
le about 5 1, the upper
ends
about
2 //
only.
The cells contain a pa-
rietal
chromatophore
and a parietal pyreno-
id; upwards in the fila-
ments
the
chromato-
phore becomes less de-
veloped and is quite or
nearly
absent
in
the
uppermost thin
cells.
The filaments are
scantily ramified bear-
ing
short branches at
all sides; just as in the
case
of the main axes
of the
erect filaments
the main
axes
of the
branches
are
thickest
below with short cells,
having longer and thin
cells above.
Upon
the
lowermost
cells
of
the
branches
the
sporangia
occur,
placed
mostly
two
together upon
a
short
pedicel
(Fig.
420 b). The sporangia
are about
8
// broad and
12
fj. long.
It is evident from this description that the plant shows great
likeness
to
the
one
found
in
Hijpnea
musciformis.
Nevertheless
some
differences
are
present.
For
instance
the
erect
filaments
grow taller and
therefore
proportionally more slender than those
x
) BORNET,
ED., Deux Chantransia corymbifera Thuret. Acrochaetium
et
Chantransia
(Bull.
Soc.
bot. France, Tome
51,
1904,
p. XX).
Fig.
420. Acrochaetium repens Borgs.
a, endophytic, basal filaments,
b,
erect filament
with sporangia. (About
175:1).
454
of the typical Acr.
repens. As to the occurrence of the sporangia
a
difference,
too,
seems
to
be
present
as
the
pedicels, bearing
the sporangia in Acr.
repens,
are often placed
directly upon the
main
filament, while
in the plant upon
Griffithsia these, in the
scanty
material
found,
are
always
placed upon the lowermost
cells
of the side-branches.
By
its
large,
widely
spreading
system
of
endophytic
fila-
ments
our
plant,
too,
reminds
very much
of
Acr.
Nemalionis
(De
Not.)
Bornet,
but
it
is,
nevertheless,
very
different when
compared with
RosENViNGES 1
)
exhaustive
description, the Acr.
Nemalionis
being
a much
taller, more
robust
and much
more
ramified
plant.
The
Griffithsia in which this plant was growing was dredged
in about
5 fathoms
of water
in the month
of January.
St. Croix: Near Buck
Island.
28.
Aeroclisetiurn phacelorhizuin Borgs.
29.
AcrochsBtium
Collinsianuin Bergs.
Syn. Acrochsetium Liagorse
Borgs.,
p.
57.
In the year of 1914 Mme WEBER in the Marine Algas of "The
Percy Sladen
Trust
Expedition"
2
)
has
described
a Chantransia
Liagorx found
on
Liagora Hawaiiana.
The
Acrochsetium
(Chan-
transia) Liagorse, which
I described a year later in the first part of
this volume, must therefore have another name, and
I propose to call
it Acr. Collinsianuin in honour of the well known American phy-
cologist,
Mr.
FRANC
S.
COLLINS, who
has
contributed
largely
not only to our knowledge of the American Acrochsetium
species,
but
to
our
knowledge
of
American
algal
flora
in
its
entirety.
I
deeply
regret
to
say
that
it
will
not only
be
in
honour
of
FRANK
S. COLLINS,
but
also
in memory
of him.
Because,
after
the MS. had
left my hands and gone to the
printers, Dr. HOWE
informed me by
letter that COLLINS,
the enthusiastic
algologist,
had suddenly
died.
His
death
is
a
great
loss
to
science, but
I
also
feel
it
as
a
deep personal
one,
having
corresponded
with
F. S. COLLINS during many
years.
x
) ROSENVINGE,
L. KOLDERUP,
The
marine
algse
of
Denmark,
Part
I,
Rhodophyceee,
p.
126.
2
)
In The Transactions of the Linnean Society of London;
2. ser. Zoology,
vol.
16,
part.
3, London
1914.
455
30.
Acrochsetiuin ernothrix
B0rgs.
31. Nemalion Schrammi
(Crn.)
B0rgs.
32.
longicolle
B0rgs.
33.
Liagora
elongata Zanard.
In
the
"Algse
of
Bermuda",
p.
99, COLLINS
and HERVEY
refer Liagora corymbosa J. Ag. to Liagora elongata Zanardini, point-
ing out that
it
is impossible to separate them from each
other.
The single dried specimens found
I have with much doubt (comp.
p.
70) referred to
L. corymbosa
J. Ag.
as
I found
its anatomical
structure
agreeing
closely with
that
of
L.
elongata.
I
therefore
now prefer to consider it as a form of Liagora elongata, in accord-
ance with the opinion
of COLLINS and HERVEY.
34.
Liagora
valida Harv.
35.
pinnata Harv.
36.
megagyna B0rgs.
37.
pulverulenta
C. Ag.
Appendix to Liagora.
Before
I
leave
the
genus
Liagora
I
wish
to
mention
here
some remarkable organisms, which
I found in several of the spe-
cies, when working out my material of this genus, and from which
the drawings here reproduced were made at the time
(Fig.
421).
When
I found these
bodies,
I was inclined to
consider them as
a kind of endophytes living in the mucous layer of Liagora. But
feeling
very
uncertain
what
to
do
with
them,
I
wrote
to
Dr.
HOWE
wishing
to
hear
if
he
also
had
met
with
them.
Dr. HOWE
wrote
to me
that
he,
too,
had
found
these
bodies
in
several
species
of
Liagora
and
that
he,
too,
felt
rather
uncertain
what
to
do
with
them.
At
first
he
was
on
the
point of describing them as representing a new genus of uncertain
family, but
later
after having made more thorough examination
he
arrived
at the conclusion
"that these
discs seemed
to
spring
from terminal
or subterminal
cells
of the
assimilatory filaments
of the Liagora, usually after rejuvenescence of the cell". Dr. HOWE
told me that he had written a paper describing the discs and their
supposed
origin, but that he had put it
aside
feeling not so sure
of the matter as he would
like to be, before putting it into print.
456
Dr. HOWE'S interesting paper
1
) has now appeared, and though
I am not
able to give any better explanation as to these peculiar
bodies,
I nevertheless wish to
give here a short description being
able in some respects to make a few additions to the description
by Dr. HOWE.
Fig.
421.
Endophytic organisms
in Liagora.
a,
a body
fixed
to
the
filaments
of
Liagora.
b,
another specimen more
magnified,
c,
transverse
section,
d,
part
of
a specimen with
sporangium.
e, a young specimen,
f, part of a crushed specimen.
(a, about 300:1;
b,
f, about 500:1;
c,
d.
e, about
275:1.)
These bodies
I have found, in common with HOWE, in several
species
of Liagora, but especially abundantly in Liagora elongata
and therefore
I
restrict my description to those from this species
(Fig.
421).
l
) M. A. HOWE, Observations on Monosporangial Discs in the Genus Lia-
gora.
(Bull.
Torrey Bot.
Club,
47,
1920).
457
The shape of the bodies, when fully developed,
is like a sub-
globular thick
disc, their diameter reaching a maximum of about
200
fjt
or possibly a little more. From the flattened upper side of
these discs long hairs arise and from the opposite under side long
rhizoids
are
given
off
(Fig.
421
a,
b).
The
hairs
are very long;
they have a well developed pore at their base, granular contents,
especially in their lower part, and thick walls. At their base they
are about
7
10 n thick
growing thinner upwards. The
rhizoids
have no granular contents;
their walls are thin. They are about
5
fjL thick. The rhizoids run down along the assimilating filaments
of the Liagora or spread
freely in the mucilage
of the host plant
(Fig.
421 a). Both hairs and
rhizoids
are
often
present
in
great
number, 10
12 or even more. The surface of the bodies consists
of the more or less
free obtuse ends
of the peripheral
cells. They
are surrounded by a thicker or thinner mucous
layer.
From a transverse section (Fig. 421 c)
it is seen that the disc
is composed
in the middle
of a parenchymatic
tissue formed
of
thin-walled, roundish-polygonal
cells. These are arranged
in
fila-
ments
radiating
towards
the
periphery and
are
subdi-trichoto-
mously
ramified
several
times.
The
growth
takes
place
in
the
peripheral
cells,
these
are
long,
thin
and,
as mentioned
above,
more
or
less
free.
In one of the transverse sections sporangia were found
(Fig.
421). These are formed from the peripheral cells and
are oval
in
shape. One
of these- was divided by means
of a transverse wall
into two spores
; the whole sporangium was sourrounded by a thick
transparent wall commonly found round
the
tetraspores. HOWE
has
in
his
specimens
found
only
monosporangia,
and
similar
bodies (comp. HOWE'S
figures)
I,
too, have often seen in mine.
Regarding the chromatophores HOWE says that they seem simi-
lar to those of Liagora but those
of the
discs
are more
red.
In
my specimens the chromatophores appear to
be a few parietal
plates.
Finally
I must add
that
these bodies are found in
all states
of development from quite small to
larger
ones.
The function of these
little bodies has yet to be made
clear.
In his paper Dr HOWE
tries to make
it evident that they
origi-
nate from the Liagora itself. He says" The truth seems to be that
these
discs
arise from
gonidia, gemma3
or
aplanospores,
derived
458
from the terminal
or subterminal
cells
of the
assimalitory
fila-
ments
of the
Liagora,
as was the view
of KimiNG 1
)
in regard
to
similar
structures in Liagora
Turneri", And HOWE
describes
and
gives
figures
of
this
continuity,
but he
points
out
himself
that
the
observed
evidences
of
direct
continuity
were
not
so
numerous
as he might wish.
I
have
not
in my
material been able
to
find any
organic
continuity between
this organism and the host-plant,
and
I am
therefore most
inclined
to
consider
it
as
an
independent
plant.
As
is
already
pointed
out
by
Dr. HOWE
it
seems both
easier
and more probable to consider these bodies as independent endo-
phytic
structures.
Finally
I can only wish,
just
as
Dr. HOWE
does, that some
one, who has access to suitable living material, would be able to
solve the question by means
of a thorough examination.
38.
Scinaia complanata
(Collins) Cotton.
Galaxaura Lamouroux,
When I worked out my material of this genus I, of course, foun-
ded my determinations on the rather recently published compre-
hensive monograph by KJELLMAN.
The material
I have collected of this genus was rather poor,
these plants being not very attractive, and rather slow and
dif-
ficult to dry and taking up much space in the bottles. Neverthe-
less through KJELLMAN'S work
I
arrived
at the conclusion that
eleven
species were present
at the
islands.
But
I want to point out that the determination of the species
from
the work
of
KJELLMAN
is
not
without
difficulty. Many
of
his
species
are
surely based
upon
scanty
material
and
are
often
at the best only varieties or forms
of the same
plant.
The highly interesting and
instructive examinations by
Dr.
HowE 2
) have amply proved that this
is the case. The fact
is that
this
well known American
investigator has
arrived
at
the
con-
r
)
KtlTziNG,
F., Tab.
phycologicse,
vol.
VIII,
pi.
90.
2
) HOWE, M.
A.,
in
Brooklyn
Botanic
Garden
Memoirs,
vol.
I,
1918,
p.
191.
459
elusion
that,
in
spite
of
the very
different
anatomical
features
found
in
the
different
forms and
upon which KJELLMAN based
his grouping
of the
species, KJELLMAN'S
"species"
of one
of the
groups
nevertheless
represent,
in
all
probability the
tetrasporic
or sexual
form
of
another
"species"
referred to another group.
For instance the species
of the sectio "Feprecwfe" of KJELL-
MAN
represent
the
sexual
plants, and
those
of the sectio "Bra-
chycladia"
the
tetrasporic
plants
of corresponding
species. And
the group Rhodura
is made up
of tetrasporic
plants whose
cor-
responding male and female plants are to be found in the groups
Microthoe and Eugalaxaura
of KJELLMAN.
How different the two corresponding forms of the same plant
are,
is best seen by comparing some
of my figures of the anato-
mical
structure
as
given
above.
Nobody
would
imagine
taht
the Galaxaura occidentals, as
it
is described and figured on
pag.
110
11,
could
belong
to
the same
species as G. marginata, the
anatomical
structure
of which
is shown in
Fig.
116.
According
to HOWE
the
forms
found
in
the West
Indies
might be grouped
in this way:
39.
Galaxaura marginata
(Sol.) Lamx.
(sexual form:
G.
occidentalis
B0rgs.J.
40.
Galaxaura
squalida
Kjellm.
(tetrasporic form:
G.
flagelliformis
Kjellm.).
41.
Galaxaura rugosa (Solander) Lamx.
(tetrasporic form:
G.
subrerticillata
Kjellm.).
42. Galaxaura
cylindrica (Solander)
Kjellm.
(tetrasporic form:
G.
lapidescens
(Sol.) Lamx.
43. Galaxaura oblongata (Ell. et Sol.) Lamx. according to Howe,
the
right name
for
G.
fragilis (Lamarck.) Kjellm.
(tetrasporic form:
G. comcms
Kjellm.).
44.
Gelidiuin corneum (Huds.) Lamour.
45.
Wrangelia
Argus Mont.
46.
bicuspidata Bergs.
47.
penicillata
C. Ag.
48.
Halymenia
Floresia (Clem.) Ag.
49.
Grateloupia
filicina (Wulf.) Ag.
50.
dichotoma
J. Ag.
51.
cuneifolia
J. Ag.
460
Cryptonemia
J. Ag.
52.
Cryptonemia crenulata
J. Ag.
J. AGARDH, Nya alger fran Mexico
(Ofvers.
k. Vet.-Akad.
Forh.
1847,
p.
11,
the
note);
Spec.
Alg.,
vol.
II,
p.
225;
Epicrisis,
p.
163.
HARVEY,
W. H., Nereis Bor.-Am., part
II, p. 184. KUTZING, F., Tab. Phycol., vol.
19,
tab.
31.
Pyllophora
crenulata
J.
Ag.,
In
Hist.
Alg. Symbolse
(Linnaea,
vol.
15,
1841,
p.
18).
ARESCHOUG,
J.
E., Icones algarum,
1847,
p.
1, tab.
II. KUTZING, Spec.
Alg.,
p.
791.
Phyllophora denticulata
Ktitz., Tab.
Phycol.,
vol.
19,
tab.
77.
Two
small
collections have been
found. One
of them was
dredged in deep water and
consists
of small plants growing
epi-
phytic upon a piece
of
coral. The plants have a small basal
disc
and a very short
stipe from which the
thallus
quickly broadens
out, the broadest
part being somewhat over
1
/ z cm.
broad.
It
is
several
times
subdichotomously ramified. The
margin
is
some-
what
sinuate and irregularly dentate.
The
other specimen was most probably growing
in shallow
water.
It
is a larger plant with much broader thallus, more than
one cm. broad, and more proliferous and, on the whole, very
ir-
regularly ramified. The margin
is sinuate with larger and smaller
teeths.
Both specimens were
sterile.
St. Croix: near White Bay. St. Jan: near Rams Head (ca. 20 fathoms).
Geogr.
Distrib.: West
Indies,
Brazil.
53.
Contarinia Magdae Web.
v.
Bosse.
54.
Cruoriopsis
spec.
55.
Peyssonnelia armorica
(Crn.).
56.
Dubyi Crn.
57.
Boergesenii Web.
v.
Bosse.
58.
Nordstedtii Web. v.
Bosse.
59.
simulans Web.
v.
Bosse.
60.
conchicola
Pice,
et Grun. ?
61.
polymorpha (Zan.) Schm. ?
62.
rubra (Grev.)
J. Ag.
63.
Hildenbrandia prototypus Nardo.
64. Lithothamnion mesomorphum
Foslie.
65.
sejunctum
Foslie.
461
66.
Lithothamnion
ruptile
Foslie.
67.
occidentale
Foslie.
68.
Lithophylluni
accretuin
(Fosl.
et Howe) Lem.
69.
caribaeum
Fosl.
70.
erosum
Fosl.
71.
intermedium
Fosl.
72.
daedalnm
Fosl.
et Howe.
73.
strictum
(Fosl.) Lem.
var. nana Fosl.
et Howe.
74.
absimile
Fosl.
et Howe.
75.
(?) propinquum
(Fosl.)
76.
prototypum
Fosl.
77.
Melobesia farinosa Lamx.
78.
Chamaedoris
Fosl.
et Howe.
79.
atlantica
(Fosl.) Lem.
80.
affinis
(Fosl.) Lem.
81.
Porolithon mamillare (Harv.) Lem.
var.
occidentalis
Fosl.
82.
Boergesenii
(Fosl.) Lem.
83.
pachydermum
Fosl.
84.
Arnphiroa
rigida Lamx.
85.
fragilissima
(L.) Lamx.
86.
Corallina
cubensis (Mont.)
Kiitz.
87.
Jania
pumila Lamx.
88.
adhaerens Lamx.
89.
decussato-dichotoma Yendo.
90.
capillacea Harv.
91.
spec.
*
92.
Sperniothamnion
investiens (Crouan) Vickers.
var.
cidaricola B0rgs.
Besides the
var.
cidaricola (comp.
p.
200), which covers the
spikes
of Eucidaris
tribuloides
quite densely,
I have come
across
a closely related form which in a similar way may densely cover
the stems of Cham&doris Peniculum to which
it
is fastened firmly
by means of the numerous short rhizoids given off from the basal
creeping filaments
(Fig. 422 a). The rhizoids are unicellular, end-
ing in a broad disc with coralliform outline. The creeping filaments
are upto 35 p thick.
462
Fig.
422.
Spermothammon
stiens (Crouan) Vickers.
a, part
of a plant,
b, part of a filament
with sporangia,
(a, about 70: 1;
b, about
140:1.)
From the creeping filaments the
erect ones
arise.
These
are mostly
simple, bearing now and then - - for
the most part in their upper end
-
one or more branches but never many.
The erect filaments are nearly cylin-
drical; they are 24
27
31
,
thick.
The length of the cells about 70-
80//.
A few tetrasporangia were found
(Fig.
422
b).
They
were
sessile,
roundish-subreniform in shape with
a thick
periferal
wall,
about
45 u
broad
and
50 //
long.
The
spor-
angia occurred upon the main
fila-
ment.
The
plant was
gathered
near
the sh
re in a rather eXP
Sed rOCky
locality;
it
had
tetrasporangia
in
.-,
mrtn^
of
Tannarv^
st
Croix: white Bay.
93.
Griffithsia globifera (Harv.)
J. Ag.
94.
Griffithsia tennis Ag.
C. AGARDH, Spec. Alg.,
vol.
II,
p.
131.
J. AGARDH, Spec. Alg.
vol.
II,
p.
84; Epicrisis,
p. 70. COLLINS and HERVEY, Alg. Bermuda,
p.
135,
pi. VI,
figs. 3839.
Griffithsia
thyrsigera
Askenasy,
Forschungsreise
"Gazelle",
IV
Theil,
Bot.,
p.
36,
pi. IX,
figs.
1 and
4.
Callithamnion tenue Harvey, Nereis Bor.-Am.,
part
III,
p.
130.
Creeping upon
some
larger
alga?
I
have
found
some
well
developed tetrasporic specimens
of this plant
(Fig.
423).
As
pointed
out
by
COLLINS
and
HERVEY
the
Griffithsia
thyrsigera Askenasy and
Callithamnion
tenue
of HARVEY
do
be-
long
to
this
species.
Regarding ASKENASY'S
description
of
the
tetrasporic
plant,
some
differences
are
certainly
present,
but
this
is,
as
indicated
by COLLINS and
HERVEY,
most
probably
due to the more luxuriant development of the West Indian plant.
Griffithsia
tennis forms very loose
tufts composed
of the
ir-
regularly ramified filaments.
It is fixed to the host plant by means
of vigorous
rhizoids breaking out from the decumbent
creeping
463
part
of the
filaments
(Fig.
423 a). The
rhizoids
are
unicellular,
having
in
their basal end
a
flat roundish,
coralliform
disc. The
rhizoids
are given
off mostly in the basal proximal ends
of the
cells near the cross walls
(Fig. 423 a), but now and then,
too, a
rhizoid (mostly
smaller)
is issued in the upper (distal) end of the
adjacent
cell.
The
ramification
is
not
very
abundant;
being
mostly
re-
stricted
to
a
few
branches
in
the
older
parts
of
the
thallus,
the upper ends of the filaments often being undivided. As pointed
out by ASKENASY a peculiarity is to be noted regarding the issue
of the branches,
these not being given
off
at the
distal end
of
the
cells, as
is ordinarily the case in related forms, but near the
basal wall
of the
cells
(Fig. 423 a).
The
cells
are nearly cylindrical
or a
little
thicker
at
both
ends; about 200 /* thick and 46 times as long. The wall
is thick
in the older parts of the thallus. Near the apex of the filaments
the young
cells become gradually shorter and a
little swollen at
their upper end.
Round the upper end
of the young
cells
is
early formed
a
dense
ring
composed
of several rows of hairs.
These are
di-trichoto-
mously
ramified
and
are
soon
shed,
long
before
the
cell
has
reached its normal size.
The
tetrasporan-
gia
(Fig.
423
b)
are
formed
upon
shorter
or longer, pyriform to
clavate, unicellular pe-
dicels, one upon each
of these. They form a
dense ring at the upper
ends
of
the
cells,
a
little
above
that
of
the
hairs
or
scars
of
these. ASKENASY found
Fig- 423.
Criffithsia
tenuis Ag
a
basal part of
a plant,
b, apex of filament with tetrasporangia.
about ten only in each
( a> about 17:1
b, about
85:1).
464
ring;
in the West
Indian
plant,
as pointed
out by COLLINS and
HERVEY,
too, about
15
are
often
present.
Mostly each filament
bears two
to
three whorls, but sometimes more than
six whorls
are
successively
developed.
The
diameter
of
the mature tetra-
sporangia
is about 100 p.
The
antheridial
stands
are
described and
figured by ASKE-
NASY;
they
are
formed
terminally upon
short
pedicels
of
one
to
three
cells
(comp. COLLINS and
HERVEY,
The
Algae
of Ber-
muda,
p.
]35). The cystocarps seem
to be insufficiently known.
ASKENASY
describes,
but
in
a
very
fragmentary
manner,
one
found by him and COLLINS and HERVEY only say that "they are
characteristic
of
Griffithsia".
The
plant was
gathered
with
tetraspores
in
the month
of
January.
It was found in shallow water near the shore in a rather
sheltered
place behind the protecting coral
reef.
St. Croix: Lime Tree Bay.
Geogr.
Distrib.: Mediterranean Sea, West Indies, New Guinea, Ber-
muda
etc.
95.
Grimthsia barbata (Engl.
Bot.) Ag.
C. AGARDH, Spec. Alg., vol.
II,
p.
132.
J. AGARDH, Spec. Alg., vol.
II,
p. 80; Epicrisis, p.
64. KUTZING, Spec. Alg., p. 660; Tabul. Phycol., vol. XII,
tab.
24. HARVEY, Phycologia Britannica,
tab.
287.
Conferva barbata Smith, Engl. Bo-
tany,
tab.
1814.
Of
this
plant
I have
twice
come
across
a
few filaments
of
female
plants.
In the one collec-
tion, found between some different
algae
gathered
at
Lt.
Princess,
St.
Croix,
a young procarp was
present.
It
is a well known
fact
that
the
procarp
in this species
is
developed
terminally upon
a
short
branchlet
composed
of
a
single
joint.
The
Fig.
424
6,
c
shows
a
young
procarp
seen
Fig. 424.
Gnffithsia barbata (Smith)
_
Ag.
a, a nearly ripe cystocarp.
b
from two
different
sides.
From
and
c, a procarp seen from two op-
this
it
is
seen
that
the
basal
posite sides,
(a, about 175: 1; b and
c, about 150:1.)
central cell bears two pencentral
465
cells and
furthermore the carpogonial branch.
If this
is normally
the case then the
difference from
Gr. globifera
is
great;
in that
species
likewise
only
a
single
carpogonial
branch
is
present,the
carpogonial branch in Gr. globifera being, as described by LEWis 1
),
formed from the second
or third
peripheral
cell.
The
cystocarps
are surrounded by an involucrum composed
of about eight cells, growing out from the upper end of the terminal
joint
cell.
These
cells
are
long and
curved
over
the
cystocarp
(Fig. 424
a).
According
to
ZANARDiNi 2
)
and HAUCK S
)
the rays
of
the
involucrum
are
either undivided
or
consist
of
two
to
three
cells.
The vegetative cells were about 100 // broad and four to five
times
as long.
The
plants
were
collected
in
the month
of
February and
March, the one in
shallow water near
the
shore, the other in a
depth
of about 30 meters.
The
Griffithsia
spec., mentioned above on pag.
208, belongs
most probably to
this
species.
St. Croix:
Lt. Princess; St. Jan:
off Cruz Bay in the sound between
this island and
St. Thomas.
Geogr.
Distrib.:
Mediterranean
Sea, warmer
parts
of
the
Atlantic
European
coast.
96. Mesothamnion
caribaeuin B0rgs.
97.
Callithamnion cordatum B0rgs.
98.
byssoides Arn.
99.
spec.
100.
Seirospora
occidentalis B0rgs.
101.
Antithamnion ButlerisB
Collins.
COLLINS,
Fr.
S.,
The Algse
of Jamaica (Proceed,
of the Amer. Acad.
of Arts and
Scienc.,
vol. XXXVII,
1901,
p.
258).
Some small fragments
(Fig.
425)
of
this
delicate plant were
found
creeping upon
Lophosiphonia
obscura.
These seem
to
ac-
cord with
the description given by COLLINS.
The main filament
reaches a breadth
of up to 30
//,
its
cells a length
of about four
time the
breadth. The
wall
is
thick.
In the lowermost
part
of
1
) LEWIS,
The
Life
History
of
Griffithsia
Bornetiana
(Annals
of
Bot.,
vol.
23,
1909,
p.
657).
2
) ZANARDINI,
Iconogr. Phycol. Med.-Adriat.
II,
p.
39,
pi.
50.
3
) HAUCK, Die Meeresalgen Deutschl. und
Oesterreichs,
p.
91.
30
466
Fig.
425.
Antithamnion
Butlerise
Collins,
a
and
b.
parts of the thallus with glands,
c,
part of the thallus
near
the
base,
(a,
b,
about
175:1;
c, about
60:1.)
the filaments
the
opposite branches are issued nearest the basal
(proximal) wall of the cells in a way similar to that found in Grif-
fithsia tennis (Fig 425 c)
;
higher up
in the
thallus, on the other
hand,
the branches
issue
always
a
little below the upper cross-
wall
of the
cells
(Fig
425 a, b)
In the basal part
of the thallus some
of the
cells are naked
or bear only a single short ramulus, but soon each
cell bears two
opposite
bran-
ches, which,when
the
thallus
rea-
ches
its
highest
development,
first
gradually
develop
ramuli
from their lower
side
and
later
from their upper
side
also.
The
rachis of the pin-
na
consists
of
about 10
cells, the ramuli on the lower side seldom of more than
3 to
4
cells, those on the upperside
of
2 to
3. The length
of the
whole pinna
is about 500 //.
The uppermost
cell in the rachis of the pinna3 is often trans-
formed into a gland-cell (Fig
425 b). This gland-cell
is short and
broad with roundish summit and has the usual transparent, ho-
mogenous contents. Now and then, too, the end
cell of the ramuli
are
transformed
into
a
gland-cell
(Fig.
425
a). The
specimens
found were
sterile.
Found once
in shallow water near the
shore.
St. Croix: White Bay.
Geogr. Distrib.
: Jamaica, Barbadoes.
102.
Antithamnion
antillanum
B0rgs.
103.
spec.
104.
Crouania attenuata (Bonnem.)
J. Ag.
105.
Spyridia filamentosa (Wulf.) Harv.
After having
finished my
description
of
this
plant
(p.
233)
I
have come
across an antheridial
plant. The
antheridial stands
467
are formed near the base
of the ramuli covering densely
several
cells.
The
antheridial
stands
were
first
observed by FARLOW
who in "The Marine Algse of New England",
p.
140,
pi. X,
fig.
1
has described and
figured them.
Tetrasporangia,
cystocarps
and
antheridia
were
found
in
the months January to March.
106.
Spyridia
clavata
Kiitz.
107.
aculeata (Schimp.)
Kiitz.
var.
typica.
var.
disticha B0rgs.
f.
inermis B0rgs.
108.
Centroceras clavulatum
(Ag.)
Kiitz.
109. Ceraminm
fastigiatum (Roth) Harv.
110.
strictum Grev.
et Harv.
111.
transversale
Coll.
et
Herv.
112.
nitens
(Ag.)
J. Ag.
113.
Laurencia
Poitei (Lamx.) Howe.
114.
papillosa (Forsk.) Grev.
115.
obtusa (Huds.) Lamx.
var.
gelatinosa
(Desf.)
J. Ag.
116.
implicata
J. Ag.
117.
chondrioides B0rgs.
118.
cervicornis Harv.
119.
Chondria
polyrhiza
Coll.
et
Herv.
The
first time
I examined
this plant
I had only a dried spe-
cimen at my disposal, now
I have come across some more material,
some
of
it preserved
in
alcohol.
In this material the group of rhizoids were not so very abund-
ant, being mostly restricted
to
the
basal parts
of the filaments
or
to
filaments becoming decumbent
or approaching other
algae
etc.
to which they could
fix themselves.
A
transverse
section shows
that
the
thallus
is
terete
(Fig.
426 6), and that the cells have very thin walls. The small central
cell
is
surrounded by four to
six
large
pericentral
cells;
at the
periphery these have,
for the most
part, some
smaller
cells, the
whole
being
encircled
by
a
thin
cortical
layer
of
quite
small
cells.
The
branches
have
rather
broad
bases
(Fig.
426
), these
30*
468
being but
slightly narrowed or not
at
all; upwards the narrow-
ing of the branches
is, for the most part, slight and gradual until
rather
suddenly,
near
the
summit,
they
start
tapering
rapidly
into the acute apex.
As
described
by COLLINS
and
HERVEY
the
tetrasporangia
are formed
in the upper ends
of the branches
(Fig.
426 a);
the
fructiferous part
is swol-
len
being
often
about
twice the breadth of the
sterile,
slender
part.
In
several
respects,
for
instance,
as
to
its
whole
appearance,
this
plant
shows
great
like-
ness
to
the
Laurencia
chondrioides described by
me,
but
on
closer
ex-
Fig. 426.
Ckondria polyrhiza Collins and Her-
vey.
a, part of thallus with a group of rhizoids
and a tetrasporic branch,
b, transverse section
of the thallus.
(a, about 17:1;
b, about 60:1.)
amination several
differ-
ences will soon be obser-
ved,
for
instance,
the
acute apex of the thallus,
the
pericentral
cells
easily
seen through the
cortical
layer,
the
different
shape
of
the
branches
especially
the
tetrasporic
ones
and the highly
deviating transverse
section.
Found with tetraspores
in the month
of March.
The specimens were
gathered
in
the same
locality
as those formerly
examined.
St. Jan:
off Cruz Bay.
120.
Chondria
atropurpurea Harv.
121.
littoralis Harv.
122.
dasyphylla (Woodw.) Ag.
123.
Acanthophora spicifera (Vahl) B0rgs.
124.
muscoides
(L.) Bory.
125.
Polysiphonia havanensis Mont.
126.
127.
128.
129.
130.
spec.
variegata. (Ag.) Zan.
sphserocarpa B0rgs.
macrocarpa Harv.
ferulacea Suhr,
J. Ag.
469
131.
Digenea
simplex
(Wulf.) Ag.
In a collection
consisting
of various alga?
I have come across
the male plant
of this
species. The
antheridial stands have
pre-
viously been known
only from
a
figure
in
KUTZING'S
"Tabulse
Phycologic*",
vol.
15,
pi.
28,
fig. m. Concerning this figure FAL-
KENBERG
in
his monograph
of the Rhodomelacese writes
p.
160:
"Die
Antheridien habe
ich
zwar
nicht
selbst
gesehen,
aber
die
Abbildung KUTZING'S
lasst wohl kaum
eine
andere
Deutung
zu,
als
dass
es
sich
bei
Digenia in der That um flache, ovale Anthe-
ridien
handelt,
die am
oberen
Ende
der
Sprosse
gehauft
stehen.
Ich
ware
eher
geneigt,
die Abbildung
auf misverstandene
eingekrummte
Blatter zu deuten, wenn ich
nicht bei Bryoihamnion analoge flache Anthe-
ridien gefunden hatte".
The male plants recently discovered by
me prove
that
KUTZING
has
had
such
a
plant at his disposal. The antheridial stands
are,
when
fully
developed,
discoid
bodies
of oblique reniform shape;
their entire
surface
is covered by the
antheridia.
A whole trichoblast
is used to the formation of the antheri-
dial
stand
just
as in the case of Bryothamnion according to FAL-
KENBERG'S
description
(1.
c.,
p.
175), and
its development takes
place in a very similar way. From an apical cell with two sides seg-
ments
are
cut
off
alternately
at both
sides.
These segments
or
branches
remain
together,
increasing
gradually
in
length
and
at the same time dividing into
smaller
cells; and
this process
is
carried on
until
the above mentioned
flat
bodies
are
formed.
The
antheridial
plant was found
in
the month
of
January
in shallow water near the
shore.
St. Croix:
Lt.
Princess.
132.
Bryothamiiion triquetrum (Gmel.) Howe.
133.
Seaforthii (Turn.)
Kiitz.
134.
Herposiphonia secnnda (Ag.) Falkenb.
As pointed out in my previous
description
of Herposiphonia.
I was most
inclined
to
consider the two
species H.
tenella and
Fig.
427. Digenea sim-
plex (Wulf.) Ag. Sum-
mit of the thallus with
antheridial stands.
(About
80:1.)
470
H. secunda as nothing else but two forms of the same plant. This
opinion
I founded on the
fact that the supposed different ramifi-
cation, being the only real difference between them, would not be
proof against a thorough examination of more extensive material,
and this point of view, that the ramification in itself is not a suf-
ficient character
of
distinction,
1
still maintain,
at any
rate,
to
a
certain
degree.
Nevertheless,
I have now come to the conclusion that we have
to
do
with
two
different
species, my conclusion being
based
on
the
fact
that
I
have succeded in finding two
very different types of anthe-
ridial
plants,
so
different
that they
necessarily must
be
regarded
as
belonging
to two distinct species. Had
these
two
different
types
shown diverse forms of rami-
fication we
might
perhaps
by means of this have been
able
to
refer
plants
with
other
fructiferous
organs,
tetraspores
and
cystocarps
to
their respective
species.
R
.
th
.
th
'e '
antheridial
stands
in
different
stages
of
both
plants being ramified
development,
c.
part
of
a
male
plant.
-.,
diffprpnrps
in
a
(a,
b, about 200:1;
c about
50:1.)
rather
peculiar way which
seems to be
characteristic
of the male
plants.
If we now leave out
of consideration
the ramification
as
a
character
of
distinction between the two
species and look upon
the
other
differences
between them
mentioned
in
the
descrip-
tions we
find that the most
essential one
is that H.
tenella
is a
more
slender plant than secunda. Taking this into consideration
I now refer the most robust form of the antheridial plants found
to Herposiphonia secunda, the other to H.
tenella 1
).
l
) The
third West
Indian
form,
H.
Pecten-veneris
(Harv.)
Falkenb.
is,
I think, nothing else but a form with recurved branchlets and summits
of branches.
Fig.
428.
Herposiphonia
secunda
(Ag.)
Falkenb.
a,
transverse section
of anthe-
ridial stand,
b, apex
of
branchlets with
471
Before
entering upon
a
description
of both
plants
I
wish
to
point
out
that
both were found
growing together upon
the
same
host
plant,
Dictyota
indica,
in
the
open
sea
at
a
depth
of about ten meters. Consequently they were both growing under
exactly the same
external
conditions,
these no doubt highly
in-
fluencing the
habit
of these
plants. They were
gathered
in the
month
of February.
So
far
as
1 know
the
antheridial
stands
of
Herposiphonia
are on the whole known only from the rather imperfect note by
FALKENBERG in
his monograph,
1.
c.,
p.
308.
The
antheridial
stands
in the
plant
referred
to H.
secunda
are formed by the trichoblasts
in the upper end
of the branch-
lets
(Fig.
428). A whole
trichoblast
is
used
to
each antheridial
stand. They show great
likeness
to those found in Polysiphonia,
for
instance
to
those
in
Polysiphonia
ferulacca,
comp. my
fig.
278.
When
fully
developed
the
antheridial
stands
consist
of
a
basal
stalk composed
(mostly)
of two
cells,
a
shorter basal one
and a longer above
it (Fig. 428); they are both without chroma-
tophores and have very thick walls. The lowermost
cell
is about
20 p high, that above from 40 // to 60
;j. long and about 60
fj. thick;
the
peripheral
wall
is about
8 p
thick.
Then
follows the
fructi-
ferous, polysiphonous
part covered
all over with the
antheridia.
It is subcylindrical, about 70
11. thick below, 55
/j. above and about
180 n long. In the specimens
I have examined
it consists of 4 to
5 segments, the
central
cells being
clearly
visible
in
the middle
(Fig.
428 a). From the middle
of the
central
cells
smaller
cells
are
given
off;
these
are
di-tri-tetrachotomously ramified several
times
in a candelabrum-like manner. The outmost
cells
are
the
antheridia.
The whole
antheridial stand ends
in
a terminal
sterile
cell,
about 50
/j. long, subpyramidal
in shape and
like the
cells in the
stalk with no chromatophores and with very thick
wall.
Fig. 428
b shows in the middle a young stage
of the anthe-
ridial stand. From this it is seen that the antheridial part of it con-
sists
of short segments becoming gradually polysiphonous.
In the male plants found, the development
of the branches
and branchlets
is much reduced.
In some
of the plants no trace
of branches
are found
at
all,
in others these are only very rudi-
472
mentarily developed; and the branchlets are developed in a very
restricted number.
The most common form of ramification found
in
the male
plant
is that drawn
in the diagram
(Fig.
429) and
also
clearly
seen in the
Fig. 428 c namely,
after a segment with a branchlet
issuing, as
it seems, from the dorsal median line, follows one with
a rudimentary branch
alternately on the right or left
side of the
stem, but always on the
opposite
side
of the stem
as the
fore-
going, then three bare
segments,
then
one
with a branchlet and
one
with
a
branch
and so on. In another
specimen
in
which
no
branches
at
all
"V
'
473
Beginning from the base, the stalk
consists in the normally
developed antheridial stands
of two
cells (Fig
430 b); the lower-
most about 12
;j. long and
20
// broad
is nearly immersed in the
tissue
of the branchlet, the uppermost about 12
16 // long and
24
fji broad has rather thick walls. The antheridial part
is nearly
cylindrical;
it
is terminated
by
a
sterile
part.
This
consists
in
the
different
spe-
cimens
of
a
va-
rying
number
of
short
cells, two to
five, or sometimes
it terminates in a
longer
tricho thai-
lie
prolongation
(Fig 430
). A few
times I have found
ramified
antheri-
dial stands where,
in
two
cases,
a
smaller
fructife-
rous branch issued
from
the
second
cell
in
the
Stalk
Fin-
and
in
another
Fig.
430.
Herposiphonia
tenella
(Ag.) Nagl.
a,
part
^ a ms^e plan^
b, transverse section of antheridial
stand,
c, apex
of
branchlet with
antheridial stand
from the third basal cell of which a sterile well devel-
Ped
trichoblastic
branch
is
given
off.
(a.
about
50:1;
b and
c, about
200:1.)
were developed in
the stalk, and from the uppermost of these
cells a well developed,
ramified, trichoblastic, sterile branch issued (Fig. 430 c). This shows
that in this species there
is a tendency not to use the whole tricho-
blast in the formation of the antheridial stands, this feature, as men-
tioned
above,
being in most cases confined to a few sterile
cells
in the upper end of the antheridial stands, in others to a shorter
or
longer
hairlike
prolongation,
rarely
to
a whole
ramified
tri-
choblastic branchlet. The whole antheridial stand is generally much
curved
in
this
species
in
contradistinction
to
the
straight
ones
in H. secunda. And while the antheridial stands, rarely more than
four,
are crowded
together
in
the upper end
of
the
branchlets
in H. secunda, these, in H.
tenella
(up to a number of ten upon
474
the
same
branchlet)
are
found
scattered
along
the
branchlet
often
one from each segment
with the
exception
of the
lower-
most. A
great number
of
seg-
ments,
10
12
or
more,
are
present in the fructiferous part
of this plant, the central cells of
which are easily observable (Fig.
430
ft);
in H. secunda,
as men-
tioned above,
only four to
five
are
present.
As
to
the
ramification
of
the
main
stem
I
have
gene-
rally found
a
single
bare
seg-
ment between those with branch -
lets and branches,
as shown in
the
diagram
(Fig.
429).
But
modification
is
often
present,
compare
e. g. Fig. 430 a where
two
bare
segments
are
found
in one
case.
In
this form
in
the main
stem, nine pericentral cells were
present, in the erect branchlet s
seven only. The diameter of the
branchlets was about 50 //.
In
a
collection
af
various
algae from
shallow water gath-
ered
at the shore
of Water
Is-
land at St. Thomas, plants with
cystocarps were found. How far
these plants really belong to H.
tenella
I dare not say with cer-
tainty. The ramification, at any
rate, was the common one an-
swering to the diagram of it given
by FALKENBERG,
1.
c.
p. 303.
As
described by FALKENBERG,
1.
c., p. 309,
pi.
3,
fig. 10 the
procarps
are formed
in the trichoblasts
in the upper end
of the
branchlets. The
branchlets,
which
bear
the
cystocarps,
become
Fig.' 431.
Herposiphonia spec, a and
b,
plants
with
cystocarps
(compare
the text),
c, part of tetrasporic plant,
(a and
b, about 22:1;
c, about 50:1.)
475
more
robust,
having much
shorter and
broader
segments
than
those
of the
vegetative
branchlets
in the same
plant. The
ripe
cystocarps are frequently placed in the upper end of the branch-
lets
(comp.
Fig.
431
#),
but
not
always.
Often
the
branch-
lets,
bearing
the
cystocarp,
get
renewed
growth,
attaining
a
considerable length and
in this way giving rise to a new branch-
let (comp.
Fig.
431
a),
these being composed
of about the same
number
of
segments
as
the
common
branchlets
and
in
their
upper end terminated by trichoblasts.
And this development may be carried on
still further.
I have
found several specimens in which the branchlet growing out below
the
cystocarp
gets
indefinite
growth
like
the
main
fdaments;
branchlets
grow
out
from
its
dorsal
side
and
it may develop
into
a
normally
built
main
axis
(Fig.
431
b).
While
in my
specimens
the
above
mentioned
three
different
cases
occurred,
FALKENBERG in his specimens has only found one form: a branch-
let
growing
out
below
the
cystocarp.
FALKENBERG
accounts
for
this
peculiar phenomenon by the increased supply
of
nutri-
tion
to
the
cystocarps, which
also
benefits
the
branchlets
and
favours the growth.
The cystocarps are urceolate with a rather long neck and a
wide opening; they are about 300^ broad and 400^
long.
The plant was found with cystocarps in the month of January.
A slender form with tetraspores (Fig. 431 c) was once dredged
in deep water. The branchlets in this form are very long; at their
base about
six
sterile segments were present followed by one to
six
fructiferous
segments
and
finally
a
long
sterile
upper
end
composed
of about twenty
long,
but
slender segments tapering
slowly upwards. The ramification of
this
plant was the same as
the cystocarpic
plants, mentioned
above.
This plant was found
at a depth
of about 30 meters in the
month of March in the sound between St. Jan and St. Thomas:
off Cruz Bay.
136.
Dipterosiphonia
deiidritica (Ag.) Falkenb.
137.
Lophosipkonia obscura
(Ag.) Falkenb.
138.
Lophosiphonia
cristata Falkenb.
In my previous examination
of this plant
I had only
sterile
material at my disposal, now
I have come across specimens with
cystocarps and
tetraspores.
476
As
always
in
the
case
of the Fam.
of the Rhodomelacess
it
is from the second joint of the young trichoblasts that the procarp
originates.
The lowermost
joint
of
the trichoblast
becomes
po-
lysiphonous,
too,
while
the
upper
end
of
the
trichoblast
soon
dies away.
Fig. 432 a shows a quite young procarp.
Fig. 432
b a more
advanced
stage
at the moment
of
fecundation. We
see here the
four-celled carpogonial branch from which the long thin trichogyne
(specimens have
been found
in which the trichogyne has twice
Fig.
432.
Lophosiphonia cnstata Falkenb.
a,
quite young procarp.
b,
more
developed
procarp
in
the stade
of
ferti-
lization,
c, upper end
of
erect
filament with
cystocarp.
d,
part
of
basal
creeping filaments with rhizoids ending in large roundish
discs,
(a and
b, about 260:1;
c, about 150:1;
d, about
60:1.)
the
length
of
the
one
drawn
in
the
figure)
protrudes;
two
spermatia are fixed to
its upper end. The
fully developed cysto-
carp (Fig. 432 c)
is oblique urceolate with a rather broad opening
in
its upper end.
It
is about 200 n long and 170 // broad.
The tetrasporangia have been found by FALKENBERG and
I
refer to his description
(1.
c., p. 500). The tetrasporangia are form-
ed one in each segment in the upper end
of the erect filaments
and
in adventitious
short
branchlets,
of which
several were
pre-
sent in the specimens found. They are
spirally arranged.
The
specimens with
cystocarps and
tetraspores were found
in the month
of
January.
Together with
Herposiphonia
tenella,
Laurencia and
blue-green
alga3
it formed low dense
crusts upon
the rocky shore
of Water
Island
at
St. Thomas.
477
139.
Bostrychia
tenella (Vahl)
J. Ag.
140.
Lophocladia trichoclados
(Mert.,
C. Ag.) Schmitz.
141.
Wrightiella Tuinanowiczii (Gatty) Schmitz.
142.
Murrayella periclados (Ag.) Schmitz.
143.
Dasya pedicellata Ag.
144.
mollis Harv.
145.
caraibica B0rgs.
146.
ocellata
(Gratel.)
Harv.
147.
corymbifera
J. Ag.
148.
Heterosiphonia Wurdemanni
(Bail.) Falkenb.
var.
typica B0rgs.
var.
laxa B0rgs.
149.
Dictyurus occidentals
J. Ag.
150.
Falkenbergia
Hillebrandii (Born.) Falkenb.
151.
Cottoniella arcuata
B0rgs.
Shortly
after the
publication
of
part V
of
this treatise, in
which
I
described
this
plant,
I
got
a
letter from
Dr. HOWE
of
New York in which he most kindly called my attention to a plant
which he some years ago had described and referred to the genus
Sarcomenia, namely
S.
filamentosa Howe 1
).
I
regret very much
that
I have overlooked
it,
as
it seems to come very near to the
plant
I have found.
Fortunately
I do not think that the mischance
I have had
in
overlooking
Dr. HOWE'S plant will have any influence on my
new genus.
If we, namely,
consider the
species hitherto
referred
to the genus Sarcomenia we will soon find out that these are very
heterogeneous, and this
fact has
also been pointed out by GRU-
Now 2
), AcARDH 3
)
and
recently by HOWE,
1.
c. Concerning
this
matter
I wish
to
quote here what HOWE
writes;
1.
c.,
p.
572:
" Sarcomenia filamentosa does not appear to be very closely related
to any
of the described
species
of this
chiefly Australian genus.
The only
other
species
to
which
monosiphonous
filaments
are
attributed
are,
so
far as we can discover, the Australian species
Sarcomenia
tenera
(Harv.)
J.
Ag.,
S.
dolichocystidea
J.
Ag.,
S.
opposita
J. Ag. and
S. secundata
J.
Ag., but these
are
all much
!) HOWE,
M.
A.,
Phycological
Studies,
II.
(Bull. Torrey Bot. Club,
32,
1905,
p.
571,
pi.
27 and
pi.
29,
figs. 111).
2
) GRUNOW, A., Algae
in Reise der Oester. Fregatte Novara, 1870,
p.
93.
3
) AGARDH,
J., Analecta Algologica,
Cont.
5,
1899,
p.
130.
478
coarser
plants with
Dasyoid
or
Cliftonioid
rather than
Polysi-
phonioid habit, and the origin and arrangement of the branchlets
and monosiphonous filaments are more or
less
different
in
all of
these.
In its delicate Polysiphonioid habit, S. filamentosa is nearer
the group which
includes
S.
miniata
(Ag.)
J.
Ag.
(the type
of
which we have
seen
in
Herb. AGARDH),
S.
intermedia Grunow,
and
S. mutabilis (Harv.)
J. Ag., but these
differ not only in ab-
sence
of monosiphonous filaments, but
also in cortex characters,
etc.; in
S.
mutabilis,
also, the branches have a marginal or sub-
marginal instead
of mid-central
origin.
The apparent incongruity of referring delicate plants
of the
miniata type
to
a genus
originally based upon the
fleshy mem-
branous
Sarcomenia
delesserioides
has
already
been
remarked
by GRUNOW and
discussed
at length by
J. AGARDH.
In placing
the
above-described new
species
in
Sarcomenia, we
accept,
for
the
present, the current conception
of the
limits
of the genus".
This shows that HOWE had some doubts when he
referred
his plant to this genus which already has so many different com-
ponents making it yet more heterogeneous. A division of it seems
therefore rather
desirable,
a beginning being now made by
clas-
sing the genus Cottoniella as a representative of the two American
species,
Cottoniella filamentosa and
C.
arcuata.
In his above mentioned letter Dr. HOWE suggested that the
two plants might perhaps be identical. However, according to the
description by HOWE this does not seem to be the case, as several
differences
are
present.
With
reference
to
those we may
first
point out that the monosiphonous filaments
in my plant
are
ar-
ranged
in
zig-zag
formation
in two rows,
as against one row in
HOWE'S. The upper ends of the branches in C.
filamentosa do nob
seem to be archshaped like those in C. arcuata. And
I have never
found
in mine
similar flattened
parts
of the
filament,
as shown
in
fig.
2 or cross sections (3 or
4) in HOWE'S figures. Nor have
1
found such a well developed cortex as
is shown in HOWE'S
fig.
9,
whilst the oldest and thickest filaments in my plant looked
like
my
fig. 336
b. On the whole my plant seems to be a much more
delicate
plant than
that
of HOWE.
Therefore
I
think we have
to do with two
different
forms.
When
I
described the
plant
1
placed
it, though with much
doubt,
in
the Fam. Rhodomelaceee among "genera incertse sedis",
479
my plant upon the whole showing so much likeness to a
Polysi-
phonia. Now,
of
course,
it has found
its
right
place among the
Delesseriaceae.
Its way
of
forming the
cortex,
the development
of which
I was not able to find out from my material, but which
is easily seen in HOWE'S plant, exactly shows
its relation to this
family.
152.
Taenioina
perpusilluin
J. Ag.
153.
Caloglossa
Leprieurii (Mont.)
J. Ag.
154.
Delesseria
tenuifolia Harv.
155.
Martensia Pavonia
J. Ag.
156.
Asparagopsis taxiformis
(Delile)
Coll.
et
Herv.
CONOLLY
has
in
"Flora",
Bd.
103,
1911,
Heft
2,
given
a
description
of the Australian
species Asparagopsis armata which
ought
to be compared with that of Asparagopsis taxiformis given
above.
157.
Gigartina
acicularis (Wulf.) Lamx.
Hypneocolax
nov.
gen.
Thallus
parasiticus, minutus,
subhemispha^ricus,
processibus
brevibus
undique
projectis,
verrucaeformis
aut
semistellarise-
formis
parte
basali
nutrici
adfixus
et cum
hospite
arete
coales-
cens.
Structura parenchymatica,
cellulis plus minus seriatis radia-
tim flabellatis; interiores majores, exteriores minores corticemque
formant. Sporangia in
cellulis externis formata in duas sporas di-
visa. Antheridia in summo filorum breviorum creata, dense congesta
totam
fere
superficiem
plantse
occupantia.
Cystocarpia
sparsa
in
singulis
plantis
pluria
in
processibus
formata,
semiglobosa
poro terminali non instructa.
158.
Hypneocolax
stellaris nov. spec.
Thallus
ca.
3
/4 mm
latus.
Guticula
crassa, -20
25
fj.
lata.
Sporangia
in
cortice formata
in duas
sporas
divisa,
long.
30
,
;
lat.
16
22
.
Cystocarpia globosa pluria
in eadem planta prae-
sentia, carposporas numerosas continentia; latitude eorum 20
22/jt.
Upon
a specimen
of Hypnea
musciformis some
small wart-
like
or
sometimes
more
stellate
bodies were
found
(Fig.
433),
480
having
shorter
processes
with
broad
bases
and
acute
or more
roundish
apices
everywhere,
except
at
the
side
facing the
host
plant. As soon
as
I observed them
I supposed that
I had to do
with a parasitic Floridean and after having found, not only plants
with
neutral
spores, but
also
antheridial and female plants, this
seemed quite clear and was also amply proved by closer examination.
The parasite occurs in
all parts
of the
host plant, upon young thin filaments as well
as
upon
thicker
main
filaments;
I
have
especially
found many
of
them upon
the
tendrils of the Hypnea. The specimens attain
the size of a pinhead, their diameter having
a length
of up
to
3
/4 mm.
As the material has been preserved
in
alcohol
I am unable to tell anything about
the colour
of the
plant.
From
a
transverse
section
(Fig.
434,
a,
b,
c) through
the
host
and
parasite
is
seen that their growing together is very inti-
mate,
the
parasite
having
a very
hyper-
plastic
effect upon
the
tissue
of the host.
Thus the epidermal layer of the Hypnea
is
quite disorganized, its cells becoming in such
a way transformed and intermingled among
the
cells of the parasite that
it
is generally
quite impossible to say, where the one ends
and the
other
begins.
The
parasite
does
not
penetrate
to any
great extent into the tissue
of the
host.
I have never found any
of its filaments between the large
cells in the medullary tissue of
the Hypnea.
The figure 434 b shows a part of a transverse section of Hyp-
nea, and
the
parasite. We see some
of the large
cells belonging
to the
central body
of
the
Hypnea, but
the very regular
corti-
cal layer
of this plant
is much damaged;
perhaps
two
or three
of the largest roundish
cells are from this tissue, but this cannot
be stated with
certainty. And after having stained the transverse
section in HOFFMANN'S violet, dissolved in glycerine and water
it
is
easily
seen
that
the
cells
of
the
parasite
and
those
of
the
Hypnea are connected by pores quite in
the same manner as de-
Fig.
433.
Hypneocolax
stellaris nov. spec. Two
plants fixed to the host
plant.
(About
8:1.)
481
scribed by RICHARDS
for Choreocolax
Polysiphoniae
1
) and thereby
showing
that we have
to
do
with
a
real
parasite.
From the transverse section
is seen that the
cells nearest to
the host plant generally are the smallest, but they grow gradually
larger. The
cells in the middle
of the tissue are roundish-polygo-
'
Fig. 434. Hypneocolax stellaris nov. spec.
a,
transverse
section
of parasite and host.
b.
part
of the same more mag-
nified.
<?, longitudinal section
of apex,
d, laminated membrane.
(a, about 40:1;
b and
d, about 250:1;
<?, about
100:1).
nal,
rather
irregular
in shape with rather thick
\valls forming a
parenchymatic tissue. The cells are more or less
filled with rather
large, roundish to oval grains
of starchs. The
cells
of the paren-
chymatic
tissue
are
usually
arranged
rather
distinctly
in
rows.
Towards
the
periphery the
cells
gradually become
smaller and
are distinctly arranged in rows, forming short filaments. The end
x
) RICHARDS,
H.
M., On
the
structure and development
of
Choreocolax
Polysiphoniae,
Reinsch.
(Proceed. Americ. Acad.
of Arts and
Sciences,
vol.
26,
1891,
p.
46).
31
482
cells
are
elongated and when they have reached
a
certain
size
they may be divided into two
cells by a longitudinal
wall, and
thereafter the
basal ends
of the
cells
are
cut
of! by transverse
walls (comp.
Fig.
434
c,
d).
The whole
plant
is
at the periphery surrounded by
a very
thick
cuticula
about
20
25 //
thick.
It
is
obviously lamellated
like Lobocolax,
as described by Hows 1
)
(Fig.
434 d).
The apex
of the projections
is composed
of a great number
of, filaments packed together and diverging
in
all
directions.
In some
of the specimens
I have found some large cavities;
I think that these originate from lobes which have grown together,
because the thick cuticula, too, was partly present upon the wall
of these.
Most
of the specimens examined were
sterile;
I have found
only four with neutral
spores, one with antheridia and
five with
carpospores.
The
neutral
spores
(Fig.
435 a)
are
formed
in
the
cortical
layer in such a way that
after the
division
of the terminal
cells
by a longitudinal wall, as described above, one of the cells becomes
the
mother-cell
of
the
sporangia.
This
cell becomes
filled
with
dense contents and increases gradually in
size.
It
is then divided
by
a
transverse
wall
into two
spores.
I
have
never
found
the
sporangia divided into more spores than two, and, as most of the
sporangia seemed quite mature,
I
feel convinced that no
further
division takes
place.
The sporangia
are about
30 // long and
16
-22
//
broad.
They
are formed
over
the whole
surface
of
the
plant.
In the male specimen found, the antheridial stands occur in
extended patches covering nearly the whole surface
of the plant.
The epidermal
cells are divided several times into thin filaments
composed
of
small
roundish
cells, the uppermost
cells
of which
become transformed into the antheridia and are gradually rounded
off and
get
loose
(Fig. 435
b).
The female plants found
all had quite or nearly ripe carpo-
spores. The trichogyne or the carpogonial branch have not been
found at
all, and
I have therefore not been able to follow the de-
velopment
of
the
cystocarps.
But,
nevertheless,
I
think
I have
l
) HOWE, M.
A., The Marine Algae
of Peru (Memoirs
of the Torrey Bot.
Club,
vol. XV,
1914,
p.
90).
483
seen sufficient to be able to refer the plant to its systematic place,
this without doubt being among the Gigartinacese, as the develop-
ment of the cystocarp seems to proceed along similar lines as in the
case
of Harveyella and
Choreocolax, though with some differences.
To judge
from
the youngest
stages found
the
sporogenous
filaments grow out, after fertilization, from the central cell in all di-
rections between the rather
loose
parenchymatic
tissue
and
send off here and there
short
ramified
filaments
from which the carpospores
are
formed.
Gradually,
as
the carpospores increase
in
size
and number,
the
cells
of the parenchymatic tissue
are
squeezed
together
in
such
a way
that
a
small
globular
space
is
formed
which
is
filled
with
the
carpospores
(Fig.
435
c).
These are roundish-triangu-
lar in shape. Their diameter
reaches
a
length
of
about
2022 //.
Near the base
of
the
cavity
I
have
seen
a
large
multilobed
cell most
probably being the auxiliary
Fi
'' 435 ' HyP ne colax
stellaris nov.
spec.
a, part
of
transverse
section with
spor-
angia.
b, transverse section of male plant.
, transverse section of a cystocarp. (a, about
200
. 1;
150:L
aftprthp fusing wUh thp
sterile cells.
I have not found
anv rarnnsto
IP
thp snnrps
ny caipc
)me, tne spc
most
probably
becoming
free by dissolving or bursting of the wall. Several cystocarps are
present
in
each
plant; they are
formed
in
the
processes, these
getting a hemispherical shape.
Compared with Choreocolax and Harveyella, as these are known
from the descriptions by SiURCH 1
) and by RICHARDS*), my plant
J)
In Annals
of Botany,
vol.
13,
1891),
p.
83.
2
) RICHARDS,
H.
M., On
the
structure
and
development
of
Choreocolax
Polysiphonise
(Proceed. Amer. Arts and
Sciences,
vol.
20,
1891,
p. 46).
31*
484
differs
from
Choreocolax by
the
clusters
of
carpospores
formed
by the sporogenous
filaments, while
in Choreocolax a
single, but
very large spore is produced at each place;
it further differs by the
lack
of any carpostome. Harveyella
differs from our plant by the
fact that the cystocarps form large extended bodies over the sur-
face
of
the plant, and are not confined to small roundish bodies
as in my plant. From both genera my plant differs by the sporan-
gia being divided
into two
spores
only.
The
plant was gathered
in shallow water near the shore
in
a sheltered
locality.
It had
tetraspores,
cystocarps and
antheridia
in the month
of January.
St. Croix: Lime Tree Bay at the south shore
of the
island.
159. (jymnogongrus
tennis
J. Ag.
160.
Kallymenia perforata
J. Ag.
161.
Catenella Opuntia
(G.
et W.) Grev.
162.
Agardhiella tenera
(J. Ag.) Schmitz.
163. Rkabdonia ramosissima (Harv.)
J. Ag.
164. Encheuma isiforme
(Ag.)
J. Ag.
165. Wurdemannia setacea Harv.
166.
Gelidiopsis
rigida (Vahl) Web.
v. Bosse.
167.
Gracilaria confervoides
(L.) Grev.
168.
ferox
J. Ag.
169.
compressa
(Ag.) Grev.
170.
caudata
J. Ag.
171.
cylindrica Bergs.
172.
usneoides
(Mert.)
J. Ag.
173.
Wrightii (Turn.)
J. Ag.
174.
lacinulata (Vahl) B0rgs.
175.
dentata
J. Ag.
176.
eervicornis (Turner)
J. Ag.
177.
Hypnea
musciforiuis (Wulf.) Lamour.
178.
cornuta (Lamour.)
J. Ag.
179.
eervicornis
J. Ag.
180.
spinella
(Ag.)
Kiitz.
181.
Gloiocladia
spec.
182. Rhodymenia
occidentalis Bergs.
183.
Coelothrix
irregularis (Harv.) Bergs.
485
184. Chrysymenia
Agardhii
Harv.
185.
planifrons
(Melv.)
J. Ag.
186.
ventricosa (Lamour.)
J. Ag.
187.
Enteromorpha Harv.
188.
pyrii'orinis
B0rgs.
189.
Uvaria
(L.)
J. Ag.
var.
occidentalis B0rgs.
190.
Coelarthrum
Albertisii
(Piccone)
B0rgs.
191. Champia
parvula (Ag.)
Harv.
192.
salicornoides
Harv.
General remarks.
Definition of Species.
It
is a well-known fact that some species show wide variation
while others
are almost constant and do not
offer any
difficulty
as to
classification.
Whilst the
classification favoured by some
writers tends
to
the formation of many small species in spite of the fact that inter-
mediate forms occur between them,
others
prefer to group
into
more comprehensive species those forms which are linked together
by intermediate
stages.
It appears to me that the middle course
is
here
the
most
convenient. When
I
have
considered
myself
able
to prove the
existence
of
such
intermediate
forms
I
have
thought
it best
to refer them to the species with which they have
most
in common.
But in order to finally decide the matter an extensive mate-
rial
is
necessary. When the material
at hand
contains only few
specimens
it
is
safer
to
classify
into
separate
species; they can
always, when more material
is
at disposal, be united
later,
if ne-
cessary.
To take an instance from the West Indian algae,
I have pointed
out that Caulerpa cupressoides
is a very variable plant, the forms
of which
are
very
diverse,
but
nevertheless these
are
all
refe-
rable
to the same
species,
as the
variations seem
to
be due
to
the
environment
and
are
connected
with
intermediate
forms.
486
Halimeda incrassata is another example. HOWE divides this species
into
several
smaller
ones,
while
I,
having
found
intermediate
stages between
the
different
forms,
prefer
to
consider them
as
belonging to the same
species.
It seems to me that we get a much better idea of the mutual
relationship
of
the
different
forms, by
connecting
those
which
are obviously related, into
larger
species, than by dividing them
up
in
a greater number
of small
ones.
This
last
renders
it
difficult
to
form
a
clear
conception
of
their mutual
affinities and
equally
difficult to compare the geo-
graphical conditions
of the
different
floras.
Some remarks concerning the algal vegetation
at the islands.
In the introductory remarks to my monograph of the West
Indian Caulerpas
I have mentioned the external conditions under
which
the
alga? upon
the whole
live, and
I
can
therefore
refer
the reader to what
1 then wrote
as to the nature and
situation
of the coast and sea-bottom and to the
fact that there
is practi-
cally no
tide
at the
islands
in
question.
. But,
as
I have not
dealt with the temperature of the^sea,
I
may give here some figures which
I owe to the kindness of Capt.
SPEERSCHNEIDER
of
the
Meteorological
Institute,
Copen-
hagen.
The numbers show
the mean temperature
for
each month
of the surface water
in the
sea
at
St. Thomas.
January
25,5
July
28,3
February 24,8
August
27,7
March
24,9
September
27,2
l
)
April
25,6
.
Oktober
27,8
May
27,2
November
27,0
June
28,4
December
26,4
I regret
that
I am not
in
a position
to
give much
inform-
ation as to the algal vegetation and the associations etc. of which
it
is composed.
I had planned to go to the islands in 1915 for the
1
)
For September a
single observation only was made.
487
purpose
of
studying
the
algal
vegetation,
as
during my
earlier
visits
I had mostly been
occupied with
the
flora,
but the
out-
break
of the war suddenly put an end
to my
preparations
for
the journey.
When an algologist who
is only familiar with
the algal vege-
tation of our Northern
seas
-
- dependent upon a rocky coast or
other firm substratum for its existence
-
- for the first time comes
in contact with the tropical algal vegetation, he cannot
fail to be
immensely
struck
with
the
extraordinary
richness
and
variety
of form of the tropical algal flora which flourishes on a loose and
yielding sea-bottom and
is formed
of types which
are
altogether
absent from the Northern
seas.
I
briefly
dealt with
this matter
for the
first time in 1898 in the book written by Prof. OVE PAUL-
SEN and myself (Om Vegetationen paa de dansk-vestindiske
0er,
Ivj0benhavn
1898,
p.
4;
also
in Botan.
Tidsskr.
Vol.
22).
Since
then
I have gone into the matter in more
detail in later papers
1
)
and therefore
I
shall not
deal
further with
it
here.
Another
really
just
as
strange
occurrence
of
alga?
in
the
West
Indies
is the vegetation which
is
fastened
to the
roots
of
the mangrove (Rhizophora
mangle). The
algse
find the rather un-
even surface
of the roots a favourable place to fasten themselves,
and the
fact that the water can
circulate
freely round the roots
also
contributes
to
favour
this
habitat.
Consequently the
result
is that those mangrove roots which grow in
the water, where
it
is
salt and not stagnant,
are overgrown by a vigorous and
often
very luxuriant
algal
vegetation.
I
have
also mentioned
this
in-
teresting
vegetation
in
an
earlier
paper,
namely
in
the
above
quoted volume published on the occasion of Professor WARMING'S
seventieth birthday.
Upon the coral reefs and upon the larger and smaller blocks
broken
off from these we find near the surface of the sea and
in
shallow
water
several
Caulerpa-iorms
covering
the
blocks
and
l
) B0RGESEN,
F., A
contribution
to
the knowledge
of
the marine Alga
vegetation on the coasts of the Danish West-Indian Islands (Bot. Tids-
skrift,
vol.
23,
1900). An ecological and systematic account of the Cau-
lerpas of the Danish West Indies (Kgl. danske Vidensk. Selsk. Skrifter,
7.
Raekke, Naturv.-mathem. Afd. IV, 5, 1907). The algal vegetation of the
lagoons in the Danish West
Indies. (Biologiske Arbejder tilegnede EM..
WARMING, den
3. Nov.
1911,
Kobenhavn).
488
stones
more
or
less
abundantly
1
).
In
additions
to
Caulerpa
many
other
algae
are
characteristic
of
such
localities;
of the
Chlorophycese we
find
for
instance
Dictyosphseria
favulosa
and
D.
van
Bossese,
Valonia
ventricosa,
V.
utricularis and
V.
ma-
crophysa
all forming smaller or larger crust-like bodies,
also
Cla-
dophoropsis membranacea occurs
fixed
as
well
as detached
form-
ing sEgagropila-]ike bodies upon the bottom. And these are joined
with Chamxdoris
annulata, Halimeda Opuntia and H.
incrassata,
Penicillus and many
others. Of
Phae.ophycese we most
frequently
find
several
Padina- and
Dictyota-species,
tufts
of
Ectocarpus,
Colpomenia
and
Hydroclathrus
etc.
and
finally
many
Rhodo-
phycese,
of which
the most
characteristic
are
Gelidiopsis
rigida,
Bryothamnion
triangulare,
Digenea
simplex,
Lauren da
papillosa,
Hijpnea-
and
Spyridia-ioTins,
Galaxaura,
Amphiroa
fragilissiwa
and other corallinaceous
alga?, Centroceras and many other species,
all
forming
larger
or
smaller
tufts
often
intermingled
between
each
other.
Upon
the very exposed
rocky
coast
of the
northwest
side
of
St. Groix
several
alga? occur
so high above the
sea-level that
they
are
moistened
only by
the
spray. Uppermost were
found
several
Myxophycess
and
small
tufts
of Laurenda
obtusa
and
L.
papillosa,
of Dilophus guineensis,
Dictyota
ciliata and Padina
gymnospora.
Amongst
these,
scattered tufts
of
Chsetomorpha
an-
tennina were found
in abundance and
lower down
Polysiphonia
ferulacea, Centroceras clavulatum and Ectocarpus breviarticulatiis. Ex-
tensive patches are formed by Aglaozonia canariensis, which covers
the very uneven rocks with
its fleshy
-
- cartilaginous red-brown
thallus; now and then
Ralfsia
expansa and
Lithothamnion,
too,
form
smaller
or
larger
crusts.
This
association
can
perhaps
be
compared
with
that
of
Callithamnion
arbuscula
at
the
Faeroes,
the
tropical
association
like the northern one
living
in such
ex-
posed
places upon steep rocks where
it
is exposed. to the whole
force
of the
sea, and some
of the tropical
algaa,
too, being able
to
retain the water
like small
sponges.
Another
characteristic
association
of
alga?,
corresponding to
the
Bangia
/ros/?ora-association
of
the
Faeroes
was
found
in
rather exposed
places upon the
steep rocky coast
at Cruz Bay,
J
) BORGESEN,
F., An
ecolog. and system, account
of the
Caulerpas,
1.
c.
p.
346.
489
St.
Jan. The components
of the West
Indian
algal coinmuntiy
consisted
of
Enteromorpha
plumosa,
Chsetomorpha
and
Rhizo-
c/otttwm-species,
Pylaiella fulvescens
etc.,
all thread-like
algse.
In
crevices
in rocks and in small caves,
especially in rather
shady
places,
several small
algse are able to grow a
little above
the surface of the sea,
so they may become rather dry when the
sea
is calm. In such places in Store Nordside Bay (Magens Bay),
St.
Thomas,
a
vegetation
was
found
uppermost
composed
of
Bostrychia tenella, together with several Myxophyceae, Chsetomorpha
antennina,
Ch.
brachygona
and
other
forms,
Struvea
delicatula,
Hypnea spinella, Centroceras clamilatum, Sphacelaria tribuloides and
furcigera,
Taenioma
perpusillum, Wrangelia
Argus,
Enteromorpha
plumosa,
Polysiphonia
ferulacea,
Ectocarpus
etc.
But
the
great
number
of
these
species
are
yet,
for
the
most
time,
covered
by the
sea,
living quite near
the
surface. The rocks washed by
the spray from the sea were covered by crusts of various Lichens 1
)
and below Ralfsia expansa and Lithothamnion were found
inter-
mingled with the Lichens.
Upon
stones and
shells
in somewhat exposed
places
crust-
like
algse
are
often found
in shallow water,
for instance Ralfsia
expansa,
Hildenbrandia
prototypus,
Peyssonnelia
etc.
And
upon
stones scattered on sandy bottom in more sheltered places in shal-
low
water
Agardhiella
tenera,
Castagnea
Zosterss,
Rosenvingea
Sanctse
Crucis,
Ectocarpus,
Hypnea
musciformis,
Spyridia
fila-
mentosa,
Grateloupia
etc. grow in
larger and
smaller
tufts.
Upon rocky and stony coasts often in bays, but also in rather
exposed localities Sargassum and Turbinaria form together an often
luxuriant
vegetation,
exactly corresponding
with
the
Fucaceous
vegetation
of the Northern
seas.
A
characteristic
algal vegetation occurs on
piers and
rocks.
over which the waves are rolling, for instance in the inner harbour
of
St. Thomas where the water was much
polluted. The most
l
) According
to the determination
of WAINIO,
I collected here:
Pannelia
lusitana Nyl.
var.
decipiens Wain.,
Pertusaria prsetervisa Wain.,
Placo-
dium
Boergesenii Wain.,
var.
squamosa
areolata
Wain.,
Placodimii
di-
placium (Ach.) Wain.; Physriu
iiitrgrata Nyl., Physcia picta
(S\v.)
Nyl.;
Rinodina pyxinoides Wain.;
Buellia
conspirans
Nyl.,
Bucllia
orcularia
Wain.; Heppia
Bolanderi (Tuck.) Wain.; Collema acarosporoidr* Wain.;
Synalissa
lichinella Wain.;
Pi/renopsis
negans Wain.;
Psorotichia
Boer-
gesenii
Wain.
490
prominent components
of
this
vegetation
are
Grateloupia
dicho-
toma
and
Gr.
cuneifolia,
Enteromorpha
lingulata,
Ulva
Lactuca,
Gymnogongrus
tennis,
Bryopsis plumosa, Hypnea
cervicornis
and
musciformis, Spyridia filamentosa and
Sp.
clavata
etc.
In deeper water
at a depth
of about
5 fathoms near Buck
Island
at
St. Croix a rich vegetation of various
algae was present;
among the most
characteristic were
Griffithsia
globifera,
Liagora
pinnata,
Wrangelia
penicillata,
Laurencia
Poitei
and
L.
obtusa,
Hypnea
cervicornis,
Gracilaria
lacinulata,
Digenea
simplex, Am-
phiroa
fragilissima,
Dilophus
Guineensis,
Dictyota
ciliata
and
D.
rolubilis,
Zonaria
variegata,
Udotea Flabellum,
Penicillus La-
mourouxii,
Caulerpa
cupressoides, Neomeris
annulata and
several
others.
In
a
similar depth
off
Frederiksstecl,
St.
Croix, was
found:
Penicillus
capitatus and
P.
pyriformis,
Udotea Flabellum and
U.
conglutinata,
Dictyota
indica,
D.
rolubilis and
D.
linearis, Am-
phiroa
fragilissima,
Jania
cubensis,
several
Galaxaura-species
Cladophora
crispula,
Champia
parvula,
Spyridia
filamentosa
and
Sp.
clavata, Digenea simplex and many
others.
In the
sea
at
St. Thomas west
of Water
Island
in a depth
of about
10
15 fathoms a vegetation composed mostly of Chlo-
rophycese and among these
especially representatives
of
Codiaceas
were
found.
Of
this
family were
present
here:
Penicillus
capi-
tatus,
P.
pyriformis
and
P.
Lamourouxii,
Udotea
cyathiiormis,
U. verticillosa and
U.
I'labellum, Avrainvillea nigricans, A. Mazei,
A.
asarifolia,
Halimeda
Tuna
forma
platydisca,
H.
incrassata
and
Cladocephalus
luteofuscus.
Of other algse:
Caulerpa
prolifera,
C. crassifolia, C. cupressoides var. flabellata
etc. Dictyosphseria favu-
losa,
Valonia
ventricosa,
Microdictyon
umbilicatum,
Anadyomene
ste'lata,
Callithamnion
spec.,
Cottoniella,
Dictyurus
occidentalis,
Gracilaria
lacinulata, Zonaria variegata and
several
others.
But the richest
flora
of
all was found
in the sound between
St. Thomas and St. Jan in a depth from about 10 to 20 fathoms.
Here was found: Dasya elegans, D. ramosissima and D.
cara-
ibica,
Lophodadia
trichoclados,
Wrightiella
Tumanowiczii,
Wran-
gelia bicuspidata and W.
penicillata, Delesseria tenuifolia, Aspara-
gopsis
taxiformis,
Gracilaria
cylindrica with
Callithamnion
corda-
tnin, Rhodymenia
occidentalis, Rhabdonia
ramosissima,
Griffithsia
globifera,
Callymenia
perforata,
Bryothamnion
Seaforthii,
Galax-
491
aura,
Chrysymenia
ventricosa,
Chr.
Enteromorpha,
Chr.
Agardhii,
Chondria
dasyphylla,
Champia
salicornoides
and
Ch.
[><i.rr//l(t,
Mesothamnion
caribaeum
etc.
Of the ffhloropkycess the most
striking forms were
Cauler/xi
Ashmeadi,
C.
crassifolia,
C. prolifera,
C.
clavifera,
C. cupressoides
var.
flabellata,
C.
Webbiana,
Struvea
elegans, Rhipilia tomentosa,
Chamgedoris
annnlata,
Udotea
cyathiformis,
U.
verticillosa,
U.
Flabellum and
U. spinulosa,
Valonia ventricosa,
Penicillus
pyrifor-
rnis,
Avrainvillea
nigricans,
Avr.
asarifolia,
Halimeda
discoideo
var.
platyloba, A?iadyo?nene
stellata,
Acicularia Schenckii,
Dict//<>-
spheeria
farulosa,
Codium
tomentosum
and
C.
isthmocladum and
several
others.
In the strait north of St. Jan between Tortola the algal vege-
tation had
another
composition.
Here Chrysymenia
Uvaria was
often found
in
large quantities.
Some remarks on the geographical position
of the West Indian algal flora.
We
see
from
the
investigation now
concluded, concerning
the
alga3 found round those West Indian islands which formerly
belonged
to
Denmark,
that we
have
dealt
with
90
species
of
Chlorophycese,
45
of
Plweophycex
and
192
of
Rhodophycea?.,
this
last mentioned being therefore by far the largest group. Compared
with
the very high number
of
788
species,
\vhich MURRAY has
included in his "Catalogue of the marine algae of the West Indian
region"
1
),
327,
the
total number found by me,
is
certainly not
a
large number.
But we must remember that
the
Myxophycese
are included in MURRAY'S list and moreover, as he himself admits,
a large number
of the West
Indian
species
in
his catalogue
are
doubtful ones, so this large number will certainly get much reduced
on
critical examination.
If we now will try to make a comparison between the West
Indian
algal
flora,
as known from
the
islands
in
question,
and
other algal
floras, a comparison with other West Indian floras
is.
of
course, the most obvious
one. But
this
I have not done here,
as, with the exception
of the Bermuda
Isles and
in
lesser
x
)
In Journal
of Botany,
1888-.su.
492
Barbadoes, Jamaica and Guadeloupe, the West
Indian region
is
still rather poorly investigated and a comparison
is therefore not
very satisfactory and besides
I
consider such a local comparison
but
of minor
interest.
On the
other hand, a comparison between the West
Indian
algal flora on the one side
of the Atlantic Ocean and that of the
Atlantic-Mediterranean area on the other
side
of the ocean, and
a
comparison between
the West
Indian
algal
flora on
the
one
side
of
the American Continent and the flora of the Indo-Pacific
Oceans
on
the
other
side
of the Continent
would
be
of
great
interest.
A
priori,
one would
be
absolutely
inclined
to
think
that
the
similarity between
the two
last
mentioned
floras
must
be
very
small
or non
existent
as
the American
Continent
reaches
towards the North
as
well
as towards the South
into
cold
seas
which makes any mixing of the
algal floras from the warm parts
of the two
oceans
impossible.
However, we
shall
soon
see
that
the
similarity between these
areas
is even remarkably
great.
In the table below
a survey
is given on the
distribution of
the West
Indian
algae in the other
areas.
493
and HERVEY'S newly published work on the
algal
flora
of these
islands.
Of the remaining
166 West
Indian
species,
112
species
are
also found in the Mediterranean and at the warmer Atlantic coasts
of Europe and
Africa and
111
are
likewise found
in
the
Indo-
Pacific
ocean.
Practically
speaking the same number
of
species
is therefore common to both of the areas in question, and the West
Indian
algal
flora may therefore be
said
to be equally related
to
both the
different
areas.
If we look
at the Chloropkycese alone we
shall
meanwhile
find
that
they
occupy
a somewhat
different
position;
of this group 90 species are found at the islands and of
these species
46, that
is more than the
half,
are common to the
Indo-Pacific,
while
only
35
are
found both
in the West
Indies
and
in
the Mediterranean and
adjacent
region
of the
Atlantic.
With
regard
to
the
Phseopkyceas the corresponding numbers
are
18 and
14. On the other hand
the West Indian representives
of
the Rhodophijcese are more
closely related
to
the
Mediterranean-
Atlantic
flora
(63
species common
to
both)
than
to
the
Indo-
Pacific ocean
(only 47
species
in common).
From the above we have
seen
that the West
Indian
alo-al
o
flora
does resemble
in
an
almost
equal
degree
the
flora
of
the
Indo-Pacific ocean and that
of the Mediterranean Sea and
adja-
cent warm parts
of the European and African Atlantic coasts
-
in the
case
of the
Chlorophycese the resemblance being even far
greater
-
- and that
in
spite
of the
fact
that
the two
areas
are
apparently
so
distinctly separated.
MURRAY was
the
first
to
point
out
this
striking
similarity.
In
his paper; "A comparison
of the marine
floras
of the warm
Atlantic,
Indian Ocean, and
the Cape
of Good
Hope"
1
) he has
compared these areas thoroughly. As to those of the Indo-Paciiie
ocean
and
the
West
Indian
he
writes:
"We
have
here
two
tropical marine
floras
cut
off from each
other by
a permanent
continental
area,
and communicating
only
via
the
Cape". And
he tries to explain in the following way how this great similarity
has arisen: "That these
floras have been periodically mingled
at
the epochs of warmer climate at the Cape seems a reasonable con-
clusion with regard
to
a group
of such
antiquity
as the
Alga3".
That some
species by passing the Cape may have been
able
to
x
)
In Phycological Memoirs edited by GEORGE MURRAY, Part
II,
1893.
494
migrate
this distance
is,
of
course, not
impossible, but
in
order
to explain the great similarity between the West Indian and the
Indo-Pacific algal flora his explanation
is not
sufficient.
It
is well
known that, owing to geological reasons, the supposition has been
adopted
that the
Pacific Ocean and
the
Atlantic have been
in
direct communication through Central America as
late
as
in the
Tertiary Period.
But
if
this
is the
case the
algal
floras
of
both
oceans
have
then had
the opportunity of easy communication.
Regarding
the
geographical
distribution
of
the
Caulerpas,
SvEDELius 1
)
has
adopted
this
explanation
as
the most natural
one.
In comparing
the
21
species
of- Caulerpas found by him
at
the
shores
of
Ceylon
with
those
found
in
the West
Indies,
SVEDELIUS discovered that no
less than twelve (according to
his
definition
of
species),
were common
to
both
areas.
SVEDELIUS
writes:
"It
is very remarkable that the tropical
algal
district
in
the Atlantic
is almost confined to the West
Indies. This probably
depends on the eastern coast of South America, just as the western
coast
of Africa
-
as MURRAY
points
out, not
offering
suitable
habitats for algal growth. But then one can scarcely assume that,
even
if warmer water washed the south coasts of South America
and especially of Africa, a more luxuriant algal vegetation should
have been harboured then than
is
the
case
to-day,
seeing how
little suited they are said to be
for algal growths
of any kind.
I
therefore
think
that
the
communication
arid
the
relationship
between
the
floral
districts
of
the
Indian-Pacific Ocean and the
West
Indies
can
be more
naturally
explained
in
another way,
i.
e.,
that
these
districts
once
had
direct
communication
over
the districts where now the Central or South American continent
separates the two
great
oceans".
Of the
11
species
of Caulerpa found
at the West Indian
Is-
lands examined by me, 9 are also found in the Indo-Pacific Ocean,
and
if
it might be proved that Caulerpa ambigua Okamura
is like
my Caulerpa
Vickersise no less than 10 are common to both areas,
the
Caulerpa
Ashmeadi,
being
the
only
specific West
Indian
species
found, having
a rather
restricted
distribution. And
just
the
fact
that, which
I have mentioned
above,
it
is
the
Chloro-
phycese, and among them especially such
old genera
as Caulerpa,
l
) SVEDELIUS, N., Ecological and systematic Studies
of
the
Ceylon
Spe-
cies
of Gaulerpa
(Ceylon Marine
Biological
Reports,
Nr.
4).
495
Dictyosphaeria,
Valonia
and
Codium,
that have most
species
in
common
in both
oceans,
while the Rhodophyceae being
surely
of
more recent origin, show less correspondence, seems to strengthen
the supposition that the great number of species common to both
oceans
is
due
to
this
earlier communication between
the
two
oceans.
In
this
connection
it
is
also
of
interest
to mention OSTEN-
FELD's 1
) conclusion regarding the marine phanerogamic plants. Of
these, 6 species which are surely the representatives of very old types,
occur in the West Indies and 4 of these are closely related to four
corresponding
forms
occurring
in
the
Indo-Pacific
ocean,
and
this
great
resemblance
is,
according
to OSTENFELD, only to be
understood by the species having migrated through the Tertiary Cen-
tral American strait into the Caribean Sea and,
after having been
shut
in
here,
they
have developed
into
the
species
which we
now
find
in the West
Indies.
In
just the same way,
in
fact, resemblances between
zoolo-
gical groups have been accounted
for.
The
result
of the above-mentioned comparison can
therefore
briefly be summed up
thus: The
algal
flora
of
the West
Indian
islands
in
question shows
a strikingly
great
resemblance
to that
of the Indo-Pacific
ocean.
This
applies
especially
to
certain,
undoubtedly very
old,
groups
of
Chlorophycese.
The
Rhodophycex,
on
the
other
hand, show
less resemblance
to those from the Indo-
Pacific Ocean, being more closely related to the algal
flora
occurring
in
the Mediterranean- Atlantic
terri-
tory.
The great similarity bet ween those two algal floras:
the West
Indian
and
the
Indo-Pacific, which
in
our
days
are
so
distinctly separated,
has
its natural
ex-
planation
in
a
prehistoric
old
connection
between
the two
oceans.
) OSTENFELD,
C.
H., On the geographical
distribution
of the Seagrasses
(Proc. Roy.
Soc.
Victoria,
27,
(N.
S.), Part
II,
1914,
p.
179).
( ISTENFELD,
C.
H.,
Havgraessernes
Udbredelse
i
Verdenshaveno,
,,Na-
turen",
1917.
496
Concluding Remarks.
During
the
war
the
Danish
Government
found
itself
compelled
to
sell
to
America
our
small,
but
beautiful
Danish
West Indian
Islands.
In
spite
of
the opposition of a
large
part
of the Danish people, and the protest, not only of many eminent
men of science, but also of many prominent commercial and naval
men,
the
Dannebrog,
after
having waved
over
the
islands
for
two and one
half
centuries, was lowered
for ever
in
1917. The
United States took over the islands in the year 1917, that
is, long
before the publication
of the
later
sections
of
this work,
so the
title
of these
later
sections
is
in
this respect
misleading.
It was in 1892 that,
I as a young man, visited our West Indian
Islands for the first time, and among otherthings began to collect and
examine the marine algae along the coasts of the islands encouraged
by
Prof. WARMING 1
) who
just
at
that time
visited
the
islands.
I, of course, chose these islands because they were Danish, and be-
cause
I thought
it our duty to study their nature.
I
little thought
to have the grief of seeing Denmark lose the islands; this has not
only been a personal loss, but also a considerable loss for the Danish
Natural
Science.
I want
in
this connection
to mention the
fact
which
Dr.
TH. MORTENSEN
and
1 2
)
have
already pointed
out,
that the sea round the
islands
is
full
of incomparable treasures,
for the Zoologist especially, on account of the great depth of the
sea
just
off the
coast, and
the
botanist
will
scarcely be
able
to
find
a more
diverse
algal vegetation than the one which
I have
found in the sound between
St. Jan and
St. Thomas and, in fact,
in
all the adjoining waters
of these
islands. The
sea has nearest
to them a depth of about 10 to 20 fathoms and a very rich vege-
tation
consisting
of
the most
interesting
types
of
algee
covers
the sea bottom. A biological station, near Cruz Bay,
St.
Jan,
for
example would always be
able
to supply the
students with
the
J
)
Professor WARMING, who
has always shown
the
greatest devotion
to
the interests of his country, has continually emphasized the young bota-
nists' duty to investigate the distant parts of our kingdom.
It was through
his
initative
that
the botanical survey
of the
Faeroes was started, and
the "Botany of the
Faeroes" was published as a result. And when
this
survey was concluded, an
investigation, on
similar
lines,
of the botany
of
Iceland was
initiated, and
as
a
result
of
this
a couple
of volumes
have already appeared.
2
) MORTENSEN, TH. og F. BORGESEN, En biologisk Station
i Dansk
Vest-
indien.
...Atlanten",
vol.
I,
1904,
p.
89.
497
most varied
material.
At
this
place one can dredge the bottom
again
and
again
and
continually
find
interesting
forms,
with-
out even being troubled by corals which often in the West Indies,
near
St.
Croix
for instance,
renders dredging
difficult.
In the introduction to the Chlorophycese
I have given a short
account of earlier collectors of algaB, but omitted to mention there
that
the
"Challenger"
expedition
also
visited
St.
Thomas
and
made dredgings and that some of the many Codiacese, which have
been found
just
at this
island, were dredged by that expedition.
Also several naval
officers on the Danish men of war, which
in the
course
of time were
stationed
at
the
islands, have made
many collections there, and though these collections have a hap-
hazard
character and,
of
course,
generally consist of
alga3 which
have
drifted
ashore
or
those
from
the
littoral
zone, we
have,
nevertheless, to thank many of these collectors for the specimens on
which many of our first descriptions have been based.
Indeed not
a
few
of
the West
Indian
Algse were
first described upon spe-
cimens from
the Danish
Isles.
While
collecting material iny procedure has always been
to
sort
the
gathered
material
immediately
on my
return
in
such
a
way
that
of
each
species
collected
some
specimens
were
dried and others
laid in
alcohol, and my determinations and ex-
aminations
are
chiefly based
upon the
last mentioned
material.
If
I
therefore, with regard to the new forms, had to speak about
"type-specimens",
in
the way that word
is
especially
used
in
America,
mine
are
mostly
to
be
found
in
bottles
and
in my
preparations.
Before
concluding
I
should
like
to thank
all
those who in
different ways have
helped me
with my work.
Besides
those
I
already have mentioned in the introduction to the sections treat-
ing of the green and the brown algse,
I should
like to convey my
warmest thanks to the specialists who have assisted me in work-
ing out certain groups, particularly Mme PAUL LEMOINE of Paris
who
worked
out
the
Melobesiese,' and Mme WEBER-VAN BOSSE
in Eerbeck who was so kind as to give a description of my collec-
tions
of Rhizophyllidacede and Squamariacese. My thanks are
also
due to
Dr. HENNING E. PETERSEN
who, by his great knowledge
of the group Ceramieae, was the best able to deal with this group.
32
498
I should also like to thank the American algologist Dr. M. A.
HOWE who sent me large collections
of West Indian
alga?, which
have been
of
great
use
to me
for
purposes
of comparison,
con-
cerning many doubtful forms.
Then
I owe a debt
of gratitude to the late Prof. W. G. FAR-
LOW
for
his
valuable
assistance and
for the
interest
he
always
showed
in my
work, and
to
the
late
F.
S.
COLLINS, who
sent
me much
valuable
material
of West
Indian
alga?, and through
his extensive knowledge
of the American
algal flora supplied me
with much useful information.
Moreover
I am highly indebted
to
Prof.
C. LINDMAN
of the
Riksmuseum,
Stockholm,
and
Prof.
N. SVEDELIUS
of
the
Bota-
nical Museum,
Upsala,
for
the
loan
of
algae
to
compare
with
my collections. Likewise
I am sincerely grateful to the Professors
MURBECK and NORDSTEDT for their courtesy in giving me access
to AGARDH'S Herbarium
in Lund.
Finally
I
seize the opportunity to thank my colleague,
Prof.
ROSENVINGE,
to whom
I owe much important information and
who,
as
editor
of Dansk Botanisk Arkiv, has
assisted with
the
reading
of the
proof-sheets.
Mr. OVE ROSTRUP has helped me with most of the drawings,
and my best thanks are due
to him
for the trouble he has taken.
Then
I should like to thank most cordially Mr. A. D. COTTON
of Kew, who has done me the great service of reading my proof-
sheets, by which those errors, which easily arise when a foreigner
has to write a language not his own, have been as
far as possible
put
right.
Finally
I want especially to thank the Trustees of the CARLS-
BERG FOUNDATION,
not
only
for the continued grant
for the re-
production of the many drawings, but particularly for the special
grant
for the printing of the last part which otherwise must have
waited, owing to the high
cost
of printing
at
present.
With this
I take leave of those beautiful small islands where
so many
of my thoughts and
so much
of my work have been
centred
for
so many
years, and the parting
is the more
painful
since the
tie, which bound
the
islands
to my native
land,
has
been severed.
INDEX SPECIERUM RHODOPHYGEARUM
ADJECTIS SPECIEBUS CHLOROPHYCEARUM
ET PH^OPHYCEARUM
IN SUPPLEMENTO COMMEMORATIS
Pag.
Acanthophora muscoides
(L.) Bory
L'H4
spicifera
(Vahl)
Borgs
259
Acrochsetium Avrainvillese Borgs
48
bisporum B0rgs
43
csespitiforme Borgs
446
Collinsianum Borgs
454
comptum Borgs
46
crassipes Borgs
20
ernothrix Borgs
59
flexuosum
Vickers
34
globosum Borgs
28
gracile Borgs
26
hormorhizum Borgs
50
Hypnese B0rgs
51
Liagorse Borgs
57,
454
netrocarpum Borgs
24
occidentale Borgs
44
opetigenum Borgs
38
phacelorhizum Borgs
54
pulchellum Borgs
23
repens Borgs
52,
452
robustum *Borgs
40, 449
Sancti Thomse Borgs
30
Sargassi Borgs
17
seriatum Borgs
32
spec
448
spec
450
unipes Borgs
35
Agardhiella
tenera
(J. Ag.) Schmitz
361
Amphiroa fragilissima
(L.) Lamx
185
rigida Lamx
1 s -
Antithamnion
antillanum Bergs
226
32*
Pag.
Antithamnion
Butlerise
Collins
465
spec
229
Asparagopsis
taxiformis
(Delile)
Coll.
et Herv
352,
479
Asterocytis ramosa (Thwaites)
Gobi
3
Bangiopsis subsimplex (Mont.)
Schmitz
10,
445
Bostrychia
tenella
(Vahl)
J. Ag
300
Bryothainnion
Seaforthii
(Turn.)
Kutz
284
triquetrum (Gmel.) Howe
282
Caloglossa Leprieurii
(Mont.)
J. Ag
341
Catenella Opuntia
(G.
et W.)
Grev
359
Callithamnion
byssoides Am
218
cordatum Borgs
216
spec
220
Centroceras clavulatum
(Ag.) Mont
241
Ceramium
fastigiatum (Roth) Harv
241
nitens
(Ag.)
J. Ag
244
strictum Grev.
et Harv
243
transversals
Coll.
et Herv
243
Champia parvula
(Ag.) Harv
407
salicornoides Harv
409
Chondria
atropurpurea Harv
255
dasyphylla (Woodw.) Ag
258
littoralis Harv
255
polyrhiza
Coll.
et Herv
254,
407
Chrysymenia Agardhii Harv
392
Enteromorpha Harv
397
planifrons
(Melv.)
J. Ag
394
pyriformis Borgs
400
Uvaria
(L.)
J. Ag
402
ventricosa (Lamx.) J. Ag
395
Coelarthrum
Albertisii
(Piccone)
Borgs
404
Coelothrix
irregularis
(Harv.) B0rgs
389
Contarinia Magdee Web.
v. Bosse
128
Corallina cubensis
(Mont.)
Kiitz
187
Cottoniella
arcuata Bergs
334,
477
Crouania
attenuata (Bonnem.)
J. Ag
230
Cryptonemia crenulata
J. Ag
460
Dasya
caraibica Borgs
319
cory/nbifera
J. Ag
323
inollis Harv
317
ocellata
(Gratel.) Harv
322
pedicellata Ag
316
Delesseria
tenuifolia Harv
344
Dictyurus
occidentalis
J. Ag
327
Digenea simplex (Wulf.) Ag
281,
469
Diptcrosiphonia
dendritica
(Ag.)
Falkb
292
Erytkrocladia subintegra Rosenv
7"
Pag.
Erythrotrichia carnea
(Dillw.)
J. Ag
7
Eucheuma
isiforme
(Ag.)
J. Ag
366
Falkenbergia Hillebrandii (Bornet)
Falkenb
331
Galaxaura comans
Kjellm
90,
459
cylindrica (Solander)
Kjellm
106,
459
delabida Kjellm
100
flagelliformis
Kjellm
93,
459
fragilis (Lamk.)
Kiitz
105,
459
lapidescens
(Solander) Lamx
95,
459
rnarginata
(Solander)
Larax
106,
459
oblongata
(Ell. et Solander) Lamx
459
occidentalis Borgs
109,
459
squalida
Kjellm
102,
459
subverticillata
Kjellm
92,
459
Gelidiopsis
rigida
( Vahl) Web.
v. Bosse
370
Gelidium corneum (Huds.) Lamx
114
Gigartina
acicularis
(Wulf.) Lamx
356
Gloiocladia spec
385
Gonwtrichum elegans (Chauv.) Le
Jolis
4
Humphreyi Collins
445
Gracilaria caudata
J. Ag
375
cervicornis
J. Ag
381
compressa
(Ag.) Grev
374
confervoides
(L.) Grev
373
cylindrica B0rgs
375
d tfentata
J. Ag
380
fferox
J. Ag
374
iacinulata
(Vahl)
Bergs
379
usneoides
(Mert.)
J. Ag
378
Wrightii (Turner)
J. Ag
378
Grateloupia
cuneifolia
J. Ag
125
dichotoma
J. Ag
124
filicina
(Wulf.) Ag
123
Griffiths ia barbata
(Engl.
Bot.) Ag
464
globifera
( Harv.)
J. Ag
-Ji H'
spec
208
tenuis Ag
462
Gymnogongrus
tenuis
J. Ag
357
Halymenia Floresia
(Clem.) Ag
122
Herposiphonia secunda
(Ag.)
Falkb
469
tenetta
(Ag.) Nagl
286,
472
Heterosiphonia Wurdemanni
(Bail.)
Falkenb
">-
I
Hildenbrandia prototypus Nardo
140
Hypnea
cervicornis
J. Ag
385
cornuta (Lamx.)
J. Ag
382
niusciformis
(Wulf.) Lamx
381
tenella
(Ag.)
Kiitz
BS4
Pag.
Hypneocolax
stellaris Borgs
479
Jania adhserens Lamx
195
capillacea Harv
198
decussato-dichotoma Yendo
197
pumila Lamx
191
spec
199
Rallymenia perforata
J. Ag
358
Laurencia
cervicornis Harv
253
chondrioides B0rgs
252
int.plicata
J. Ag
251
obtusa (Huds.) Lamx
247
papillosa
(Forsk.) Grev
246
Poitei (Lamx.) Howe
245
Liagora corymbosa
J. Ag
70,
455
elongata Zanard
67,
455
megagyna Borgs
77
pinnata Harv
74
pulverulenta
C. Ag
valida Harv
70
Lithophyllum absimile
Fosl. et Howe
165
accretum
(Fosl.
et Howe) Lem
159
caribseum Fosl
160
dsedalum
Fosl. et Howe
162
erosum Fosl
160
intermedium Fosl
161
propinquum
(Fosl.)
166
prototypum Fosl
167
strictum
(Fosl.) Lem
164
Lithothamnion mesomorphum Fosl
155
occidental Fosl
157
ruptile
Foslie
156
sejunctum
Foslie
156
Lophocladia
trichoclados
(Mert.,
C. Ag.) Schmitz
202
Lophosiphonia cnstata Falkenb
297,
475
obscura
(Ag.)
Falkenb
294
Martensia Pavonia
J. Ag
348
Melobesia
affinis
(Fosl.) Lem
176
atlantica
(Fosl.) Lem
175
Chanisedoris
Fosl. et Howe
173
farinosa Lamx
170
Mesothamnion caribseum B0rgs
"08
Murrayella periclados
(Ag.)
Schmitz
314
Nemalion
longicolle B0rgs
64
Srhrammi
(Crn.)
Borgs
61
Peyssonnelia armorica
(Crn.)
136
Boergesenii Web. v. Bosse
137
conchicola
Pice,
et Grunow.
.
144
Tag.
Peyssonnelia Dubyi On
1 :;r.
Nordstedtii Web. v. Bosse
1
I'
i
polymorpha
(Zan.) Schm
1
}."
rubra
(Grev.)
J. Ag
lie,
simulans Web. v. Bosse
142
Porolithon
Boergesenii
(Fosl.) Lem
1 7>
mamillare (Harv.) Lem
177
pachydermum
Fosl
1 si
i
Polysiphonia ferulacea Suhr,
J. Ag
277
havanensis Mont
2<',i;
macrocarpa Harv
27
1
spec
268
sphserocarpa Borgs
271
variegata
(Ag.)
Zanard
269
Rhabdonia ramosissima
(Harv.)
J. Ag
''>*'>'*
Rhodymenia occidentals Borgs
:'>^7
Scinaia complanata
(Collins)
Cotton
s ">
Seirospora
occidentalis Borgs
222
Spermothamnion
investiens
(Crn.)
Vickers
200,
461
Spyridia aculeata (Schimp.)
Kiitz
237
clavata
Kiitz
235
filamentosa
(Wulf.) Harv
233, 4M
Tsenioma perpusillum
J. Ag
33s
Wrangelia Argus Mont
111'.
bicuspidata Borgs
IIS
penicillata
C. Ag
1 -(
)
Wurdemannia setacea Harv
-I'^
Wrightiella Tumanowiczii (Gatty) Schmitz
310
Blastophysa rhizopus Rke
1
1
'>
Caulerpa
fastigiata Mont
430
Vickersise Borgs
43i
i
Chsetomorpha brachygona Harv
421
gracilis
Kiitz
423
Cladophora
utriculosa
Kiitz
Endoderma vagans Borgs
41^
ventriculosum Borgs
420
viride (Reinke)
Lagerh
1
1
'1
Halimeda discoidea Decsne
I -'
'
Phseophila Floridearum Hauck
415
Rhizodonium Kerneri Stockm
424-
12
1
Kochianum
Kiitz..
424127
Ascocyclus Hypnese Borgs
435
Dictyerpa Jamaicensis
Collins
Pag.
Ectocarpus
clachistseformis Heydr
435
rhodochortonoides Bergs
433
variabilis Vickers
434
Myrionema vulgare Thur
44]
Myriotrichia
occidentalis Borgs
437
Padina Howeana Bergs
442
Pylaiella fulvescens
(Schousb.) Born
431
Rosenvingea
Sanctse Crucis B0rgs
441